Injuries to Jeremy McGovern and Travis Cloke mean massive headaches for West Coast and Collingwood as their AFL seasons reach a crucial phase.

The Eagles lost McGovern with a serious hamstring injury in the third term of Saturday’s twilight match at Etihad Stadium, on the way to a 31-point win over Collingwood.

West Coast’s inaccuracy kept the game tighter than it should have been but the 11.21 (87) to 7.14 (56) win kept them in second spot.

It is also the first time they have beaten Collingwood in Melbourne since round eight, 2003.

McGovern started the game on Cloke, who went off in the first term with a suspected torn calf.

Without McGovern, West Coast are now back to where they were at the start of the season – desperately searching for a key defender or two.

Then they lost Eric Mackenzie and Mitch Brown to knee reconstructions.

It means 19-year-old Tom Barrass could make his AFL debut next Sunday against Sydney and their wealth of key forward options.

After the home game against the Swans, the Eagles play Gold Coast away and then host reigning premiers Hawthorn before the Western Derby against top side Fremantle.

“When you can’t run off or even jog off, it’s probably between a three and five-week injury,” coach Adam Simpson said of McGovern’s injury.

“We don’t bat overly deep on tall defenders.

“We can’t rely on one player … our players have been standing by that all year.

“We have to find a way to play without McGovern.”

But Simpson praised his team’s self-belief throughout this season and said they would try as much as possible against the Swans to keep the ball in their half of the ground.

In a bruising game, Scott Selwood (knee), Josh Hill (shoulder) and Xavier Ellis (elbow) all had to go off.

They played out the match but Simpson admitted they were sore afterwards.

Cloke’s injury means Collingwood will have to restructure their attack.

“He felt a bit of a ‘pop’, so it’s likely to be a calf tear,” Magpies coach Nathan Buckley said.

It was Collingwood’s fourth-straight loss and if Adelaide win the Showdown on Sunday, the Magpies will drop out of the top eight.

“We’re just not quite good enough, are we?,” Buckley said.

“We’re just that little bit off at the moment.

“We’ve had periods through that month where our footy has looked more than likely.

“We’ve earned the right to win games … not tonight but over the last month.”

Brownlow Medallist Matt Priddis and Mark LeCras were best for the Eagles, while Steele Sidebottom and Marley Williams stood out for Collingwood.

“We were really pleased, really proud of our players,” Simpson said of the win.

“It was a big ask, a big challenge to come over here and play against a team who is just as desperate as we are.”

Magpies ruckman Jarrod Witts was reported for tripping Priddis.