In 2016, Leeds Rhinos and Huddersfield Giants found themselves in the bottom four come the Super 8s split, despite the former winning the treble and the latter finishing fourth in 2015. The 2017 season witnessed Warrington Wolves and Catalans Dragons having to endure the ignominy of the Middle 8s to fight for their Super League survival. The new structure - since its inauguration in 2015 - has often sprung a surprise or two with sides that should be near the top end of the table - mainly because of investment levels and the quality within their squads - struggling for whatever reason and having to battle against promotion-hungry Championship sides for the right to play in the top flight the following year.

Another top Super League side could well be in danger in 2018.

Wigan Warriors

For a team that won the Super League Grand Final in 2016, the World Club Challenge in 2017 and one that came up just short in the 2017 Challenge Cup Final, Wigan Warriors' inclusion may seem, at first glance, unwarranted. Yet, the World Club Challenge has little prestige in Australia: NRL teams barely give it recognition while the Warriors' Super League season was, on the whole bitterly disappointing; the Lancashire club finished seventh at the end of the regular season and sixth at the end of the Super 8s. They won 14 games, drew three and lost 13; is this a sign of perhaps worse things to come in 2018?

Injury list

Wigan fans and some Rugby League fans, in general, may point to the fact that Wigan was beset by injuries in 2017.

But, the likes of George Williams, Tommy Leuluai, and Sam Tomkins were still in and around the team for much of the year. And, blaming rotten form on injuries - though the Warriors did have 11 out at one stage in 2017 - does not cut it anymore in Super League. Squad depth is built up for just that reason and if the incoming players are not good enough to replace those on the sideline then that is the coach's and board's fault for not investing in the right players.

Castleford Tigers had 12 out - including important half-back Ben Roberts - at one stage in 2016; even loose-forward Adam Milner had to play on the wing in an away clash at Catalans. And the Tigers rallied towards the back end of that year, winning five from seven in the Super 8s to finish fifth. Widnes, a side that, by a point in the 2017 season, was fielding a team that would have looked more at home in an academy game, were barely given airtime about the number of injuries they had suffered; Wigan's injury problems were, apparently, more severe.

Wigan head coach Shaun Wane hardly went a week without bemoaning his side's injuries, probably he knew he was becoming increasingly under pressure to perform.

Shaun Wane

A Wigan legend, Shaun Wane is a head coach that must deliver in 2018. Since taking over at the end of 2011, Wane has coached the Warriors to one League Leaders' Shield, two Grand Final victories, one Challenge Cup victory and a World Club Challenge triumph. Though this may seem impressive, he has been in charge for six seasons; his predecessor Michael Maguire coached Wigan to a League Leaders' Shield (2010), one Grand Final victory (2010), and one Challenge Cup success (2011) in just two years. That is just three major honors in two years while Wane has achieved five in triple the amount of time.

Wane is also coming under serious fire from his own set of supporters. And, is there any real wonder? At times in 2017, the Warriors looked bereft of ideas with very little attacking flair on show. Wigan stumbled through the 2017 season; their boring style of play has done little to improve the support for Wane and things need to change fast if Wane wants to keep the fans on side.

Recruitment and outgoings

Though the injuries Wigan suffered in 2017 are unlikely to be repeated in 2018, the Warriors have added only two new signings to their squad for 2018. The relatively unknown forward Gabriel Hamlin and former Wigan player Dan Sarginson are not exactly the type of signings to inspire fans to buy a season ticket.

And, the frustration of Wigan fans has been exacerbated by the recent news that Wigan stalwarts Anthony Gelling and Michael McIlorum have left the club. The departure of the latter, in particular, has left many fans questioning what is happening. Yes, Wigan has a bright star - Josh Ganson - waiting in the wings to take over the hooking duties in the future, but he surely won't be thrown into the deep end straightaway in 2018. This leaves Sam Powell to become Wigan's No.9. This is hardly going to strike fear into the heart of the opposition.

Wigan does have a genuine problem though; Sam Tomkins and Tommy Leuluai - two players who have been key for the Warriors in the past - are past their best - Tomkins even failed to earn an England call-up for the 2017 World Cup despite the absence of Zak Hardaker. And, with - arguably Wigan's most vital player - Sean O'Loughlin spending more time on the sideline than the field, others will have to step up.

George Williams is a fantastic half-back but he cannot do it on his own; too many times in 2017, Williams had to try to create something out of nothing because of the lack of help from those around him. The Warriors need to give him a half-back partner that controls the game - much like Marc Sneyd at Hull FC or Luke Gale at Castleford - so that Williams can be let loose with his superb running game. Something needs to change at the club or 2018 could be a year to forget for the Warriors. It could be left down to chairman Ian Lenagan to provide that change if Wane fails to hit the heights that Wigan fans have come to expect.