National Women's Soccer League teams have been focusing on recruitment ahead of the impending 2018 campaign, with the hope that they can knock retaining champions the Portland Thorns off their perch.

It has certainly been a turbulent few months for the NWSL. In November it was announced that two-time NWSL champions FC Kansas City were folding and in turn, the Utah Royals would be forming the newest NWSL expansion team, under the Real Salt Lake organisation.

Disappointing announcements

However, it didn't end there in terms of disappointing announcements as one of the country's oldest women's soccer teams, the Boston Breakers, announced the collapse of the club shortly after the NWSL College Draft.

Having participated in every professional season since the club's re-establishment into the WPS in 2007, it came as a major shock to many in women's football. But most of all the deepest dejection would have been felt by the Boston players. The vast majority of the team had to deal with the inconvenience of relocating to a different state merely weeks before the start of pre-season.

The Boston Breakers' players were taken in an NWSL Dispersal Draft, with top pick Rose Lavelle heading to the Washington Spirit. Whilst there has been plenty of action concerning the decline of some of the NWSL's longest-serving teams - we've also seen plenty of movement in the transfer window which will keep fans eagerly anticipating the start of the new footballing calendar.

As the 2018 season draws closer we look at the 10 biggest transfers going into the new campaign:

1.Sam Kerr - Sky Blue FC to Chicago Red Stars

A day after the NWSL Draft, where Washington Spirit took Stanford midfielder Andi Sullivan with the number one pick in the first round, there was a huge draft-day deal taking place for three of the league's biggest stars -which many are claiming to be the biggest player-trade in NWSL History.

Undoubtedly, the blockbuster trade of the season was a three-player move which saw Sam Kerr, Christen Press and Carli Lloyd all moving to new locations.

The Matilda's superstar has been claiming accolades left, right and centre recently coming off the back of a 2017 campaign, which has pushed the striker to the forefront of the sport and arguably proved that she is the best player in the world.

The plaudits have poured in - with an Asian Football Confederation's Women's Player of The Year, NWSL's Most Valuable Player, ABC Sports Personality of The Year and most recently Young Australian of The Year under her belt.

Kerr will now hope that these individual honours can help her new team claim the elusive NWSL Championship, a feat she was so close to achieving with the Western New York Flash in 2013.

As the Australian departs Sky Blue FC she leaves behind quite a legacy. The Matilda's star found the net 39 times in 2017, this included four hat-tricks, two for club and two for country, and five braces which included three for the national side.

Chicago Red Stars will be hoping that Kerr can bring the same form to Illinois and replicate the type of scoring form which saw her score four goals in one game and break the NWSL all-time goal-scoring record with 37 to her name.

2. Christen Press - Chicago Red Stars to Houston Dash

The Houston Dash acquired the experienced U.S National Team forward Christen Press via a trade with the Chicago Red Stars, which saw Carli Lloyd move in the opposite direction alongside Canadian forward Janine Beckie.

The 29-year-old has proved herself as a proven goalscorer for both club and country - after scoring 36 goals in 68 appearances across four seasons for Chicago and netting an impressive 44 goals in 96 appearances for the national team, since earning her first cap in 2013.

Press will certainly have to maintain this form for the Red Stars as she is now part of a Dash side who have a stacked front line, including the likes of Kealia Ohai, Rachel Daly and Lindsay Agnew.

However, even with such competition for places in Houston, new coach Vera Pauw has asserted that Press will "determine where she plays" and most importantly will be "the first name on the [team] sheet".

This will come as no surprise considering the stature of the player and the fact that she will now take over as the face of the team, following Lloyd's departure.

3. Carli Lloyd - Houston Dash to Sky Blue FC

Sky Blue FC acquired two-time FIFA Women's World Player of The Year and New Jersey native Carli Lloyd from the Houston Dash, in a trade which saw team-mate Beckie and Chicago Red Stars forward Jen Hoy also move in the same direction.

For the 35-year-old it is a move which brings her home. Lloyd requested a trade to Sky Blue to be close to her husband who lives in South Jersey and the Rutgers graduate has certainly had a distinguished career since making a move away from her home state.

The Delran native made her debut for the U.S Women's National Team in 2005 and since then she has collected 247 caps and scored 98 goals in the process, whilst making a name for herself as a 'big-game player'.

Lloyd delivers on the grandest of stages and this was most apparent after her phenomenal performance in the final of the 2015 Women's World Cup. The current U.S captain completed a hat-trick in the opening 16 minutes of the final against Japan in Canada.

Yet, it will also be Lloyd's experience which will pay dividends for Denise Reddy's side this season. Since Kelley O'Hara's departure to the Utah Royals, the Jersey team have added seven players under the age of 25 to their roster.

4. Sydney Leroux - FC Kansas City to Orlando Pride

The Orlando Pride added yet another Women's World Cup champion to its roster in February, acquiring the rights to forward Sydney Leroux in a trade with Utah Royals FC. The exchange saw Utah receive a first-round pick in the 2019 College Draft.

For Leroux, the move allows her to reunite with husband Dom Dwyer who recently signed a long-term deal with MLS side Orlando City.

The 27-year-old will join a frontline boasting the likes of Marta and Alex Morgan setting up a potent attacking force for the Pride on the pitch. Off the pitch, Leroux links up with former coach Tom Sermanni who she knows well from the coach's time managing the US National Team.

Leroux burst onto the international scene in 2012 and has not only scored 35 goals in 77 appearances but she was also part of the US winning squads at the 2012 London Olympics and the 2015 WWC.

Domestically, the UCLA Bruin has played for Boston Breakers, Seattle Reign, Western New York Flash and most recently FC Kansas City.

After making her comeback following the birth of her son Cassius in 2016, she led FCKC last season scoring six goals in 23 appearances and adding two assists.

Orlando Pride will be hoping that Leroux can help them build on last season's semi-final finish.

5. Allie Long - Portland Thorns to Seattle Reign

In another blockbuster trade, it was announced that long-term Portland Thorns midfielder Allie Long would be leaving the Rose City in exchange for the rights to Australian forward Caitlin Foord and a second-round draft pick in 2020.

Long has been a stalwart for the Thorns since the league's inaugural season. During her five seasons with the club, she has tallied 30 goals, 13 assists, twice named to the NWSL Best XI and scored the winning goal in the semifinals of the 2013 NWSL playoffs.

Her persistent hard work and performance rightfully earned the 30-year-old a well-earned call-up to the USWNT and also a spot on the 2016 Rio Olympic roster.

6. Caitlin Foord - Seattle Reign to Portland Thorns

Long makes way for 2016 Asian Women's Footballer of The Year Caitlin Foord. Seattle acquired the rights to Foord from Sky Blue FC for Katie Johnson and Rebekah Stott.

The 23-year-old spent three seasons with Sky Blue earning second XI honours before leaving the NWSL in 2015.

Despite her mere 23 years, the versatile Matilda is experienced on the international level with 60 caps for the national team and having won Young Player of The Tournament at the 2011 Women's World Cup.

Currently playing for Sydney FC in the W-League, Foord has faced a major set back on her return to the NWSL. The New South Wales native was subbed off at half-time of Sydney's W-League semi-final victory over the Newcastle Jets after rupturing her Lisfranc ligament. It is unclear how long Foord will be out but it is suggested that this type of injury can often keep a player out of action for 3-4 months.

7. Kelley O'Hara - Sky Blue FC to Utah Royals

Inevitably new Utah Royals manager Laura Harvey had to bring in some big names ahead of the club's inaugural season.

And she certainly did that at the turn of the year as the Brit acquired USWNT star Kelley O'Hara, along with midfielder Taylor Lytle and a third-round pick in the 2018 NWSL Draft.

O'Hara, who joins Becky Sauerbrunn as the second USWNT defender on the Royals roster, has predominately played as a full-back for her country, but has had considerable success further forward for Sky Blue and Harvey is also likely to use the Georgia native in a similar attacking role.

A Hermann trophy recipient during her time at Stanford, O'Hara is known for her marauding runs and excellent service into the box and it is never in doubt that trading KO must have been a difficult decision for the Sky Blue coaching staff.

8. Steph Catley - Orlando Pride to Seattle Reign

Australian defender Steph Catley was acquired by Seattle Reign in exchange for midfielder Christine Nairn and defender Carson Pickett.

Tom Sermanni, a manager who is often reluctant to trade players who have given their heart and soul to the team, enabled Catley's move to the west coast to reduce her travelling time whilst on Australian National Team duties, which she believes had detrimental effects on her body last season.

The experienced international scored the first goal in Pride franchise history and will be a real asset for Seattle this season.

9. Jodie Taylor - Arsenal Ladies to Seattle Reign

It was little surprise to Arsenal Ladies fans when England striker Jodie Taylor announced that she would leave the Women's Super League for a six-week stint in Australia, before joining Seattle Reign.

The 31-year-old has spent most of her career outside of England - with spells in Australia, Sweden and the States - so it was inescapable that a move would be imminent.

A prolific goalscorer, Taylor won the golden boot at Euro 2017 with five goals in four games.

During her time down under Taylor was most recently part of the Melbourne City side to win their third championship in three years, scoring the second goal in a 2-0 win over Sydney FC at Allianz Stadium.

10. Rose Lavelle - Boston Breakers to Washington Spirit

Washington Spirit acquired Rose Lavelle at the end of January, albeit via the number one pick in the NWSL Dispersal Draft from Boston Breakers, not via trade.

The 22-year-old national team starlet will be a worthy addition to an already talented squad, joining fellow national teammates Andi Sullivan, Mallory Pugh and Taylor Smith in the capital. Alongside Rebecca Quinn, the Spirit has a legion of young players who have big futures on the international stage.

Following a hamstring injury, Lavelle spent most of 2017 on the sidelines. The Wisconsin Badgers return to the women's national team came in September against New Zealand, but yet again Lavelle suffered an injury after 33 minutes.

After her selection as the number one pick in the 2017 NWSL Draft, Lavelle made an impressive start to her professional career and with such skill and game-changing prowess she is expected to make an even bigger impact on her return.