The 21-year-old bull had a stellar debut season in 2012 but injuries have cruelled him since. With Dangerfield likely to depart and Scott Thompson heading towards 33, the Crows need Crouch to take over the heavy lifting - if they are to push towards the top four in 2016.
Adelaide has several fit rebounding defenders, including Brodie Smith, Rory Laird, and Jake Lever, so Jaensch's return from an ACL injury isn't make-or-break. Yet Jaensch, who turns 26 in September, has a great knack for intercepting marking and would only help the Crows' cause.
Injuries troubled Dayne Beams in 2015, but his young brother suffered worse overall. Claye Beams hasn't played since June. The half-back is a hard nut who'll do a lot for the Lions' collective attitude when he returns.
Almost every AFL fan knows about Thomas' strong relationship with former Collingwood and Carlton coach Mick Malthouse, so it's ironic that "Daisy" only lasted one game after Mick was sacked. People forget how damaging Thomas can be when fit, and the Blues will hope he can recapture that form in 2016.
The tenth pick from the 2013 draft still hasn't made his senior debut, thanks to recurring hamstring problems. Some commentators are piling the pressure on Collingwood coach Nathan Buckley, but between Freeman, Matt Scharenberg, Jordan de Goey, and Darcy Moore, "Bucks" has a lot of talent to potentially develop in 2016.
The Dockers surprised a few observers by taking Apeness with pick 17 in the 2013 draft. Due to injuries, the raw ruck prospect hasn't had many chances so far. He'll probably take a long time to develop, however, so he might not see action in 2016 - even if fit.
Crowley's future remains in limbo after he was suspended for 12 months for taking a banned substance. He'll be technically available next month, but at 31, he'll have to put in a special effort to come back in 2015 or even 2016.
The Suns spent most of 2015 without four of their five best midfielders, including Gary Ablett and David Swallow. Jaeger O'Meara's early-season injury was an omen of things to come. The third-year player is already one of the most important cogs in the Gold Coast midfield machine.
Prestia had a stunning year in a woeful team during the first part of 2015, holding up in the competition's top-ten possession-getters. His inside grunt and on-field leadership will benefit the Suns hugely when he returns.
The 195cm defender was supposed to be the number one man in the Giants' defence by now, but consecutive ACL injuries have spoiled his career. He turns 27 in October and will be an important mature body in defence if he can get back on the park.
The number two pick in the 2014 draft - whom many thought would be number one - has signed a new deal with Melbourne despite not playing a game. Alongside Angus Brayshaw, Bernie Vince, Nathan Jones, and Jack Viney, he's the future for the Dees.
Doubts still hang over Trengove's AFL future after chronic foot injuries robbed him of nearly two whole seasons. The Demons generously offered him a contract extension anyway, but the former co-captain will need to prove himself in 2016 if he's to stay on.
North Melbourne's first pick in the 2014 draft was told to "expect to play" in 2015, but a shoulder injury derailed that plan. Fans are always hearing about North's need for a "gorilla" in defence, and at 197cm, Durdin could be the player the club needs.
The former Lion was crucial to Port Adelaide's success in 2014, with his blistering outside run. He'll do a lot to reignite the team's running game when he returns in 2016. With his 23rd birthday next month, Polec has the potential to be an important ten-year player for the Power.
Lee was considered a potential successor to Nick Riewoldt until an ankle injury wrecked his season. Now he's fallen behind Josh Bruce and Paddy McCartin in the pecking order, with Tim Membrey also in the equation. He mightn't even make it to 2016, but if he does, he'll need to perform.
The luckless Sydney defender is already questioning his future, having not played since the 2012 grand final. Yet as Daniel Menzel recently proved, miraculous returns are possible, and the football community would love to see Johnson return in 2016.
The rookie-listed ruckman made his debut in the last round of 2014, but a persistent groin injury has kept him without a game in 2015. Meanwhile, Toby Nankervis has stepped ahead as back-up ruckman. Naismith will have to fight to hold his spot on the list.
Many spectators thought West Coast's season would be ruined when the stellar full back went down with a knee injury. Instead, the Eagles have transformed into genuine premiership contenders. If they can't go all the way in 2015, they're poised for a terrifyingly good 2016 when Mackenzie returns.
West Coast's centre half back was ruled out for the season just two months after Mackenzie went down. McGovern, Schofield, and Hurn have played fantastically as an undersized defence, but like Mackenzie, Brown will be a massive boost to West Coast's back-line when he comes back.
Like the Eagles, the Bulldogs have stunned spectators in 2015, despite the loss of key personal - including a captain and coach. Incredibly, Liberatore mightn't be assured of an immediate return in 2016, with the Footscray midfield performing so well without him. He remains an elite inside midfielder, albeit with off-field issues, so it'll be interesting to see how he figures into the Dogs' future plans.