WEST COAST coach John Worsfold says he is unsure how bad the injury sustained by Dean Cox is after the Eagle suffered back spasms during the 20-point loss to Collingwood.

The star ruckman was substituted out of the match midway through the third quarter

Worsfold said the 30-year old suffered a hip-related back spasm before eventually being thrown the red vest though the Eagles coach kept his cards close to his chest as to the availability of Cox for next weeks clash against the winner of Sunday's elimination final between Carlton and Essendon.

"Obviously he is a key part of the way we play," Worsfold said on the loss of Cox during the match.

"He went back out to try and see if he could run again, but it seized up again pretty quickly."

The injury overshadowed a brave performance from the Eagles, who were looking for their first victory over Collingwood since 2007.

The Eagles were 26 points behind the Pies at three-quarter time, however they mounted a stirring revival to reduce the deficit to just seven points late in the last term.

Costly misses to Luke Shuey and Scott Selwood during the frenetic final quarter proved costly for the Eagles but Worsfold believes the fight back shown by his young group was a testament to his side's resilience uncovered this season.

"I thought the boys challenged themselves to play throughout the four quarters and there wasn't a big margin on the scoreboard… to get it to seven points and have the game alive with a few minutes to go was exciting," he said.

Despite dominating the hit-outs 50-29 on the back of a stellar performance by Nic Naitanui, the Eagles midfielders were overshadowed by their Collingwood counterparts, who won the clearances 53-31.

Worsfold believes his team must be better prepared for the intensity that ultimately comes with playing finals.

"It's a pretty intense game and a lot of pressure. We didn't cope with the pressure as well as we believe we can. The players will learn from that," he said.

"It felt like we were just a little bit short of the class of Collingwood - not the effort but the class."

"I think we matched them in intensity and effort but they showed the way with clean ball handling and clean ball use. We just made some errors that at times may have got us more inside 50s and more scoring opportunities, but we didn't quite capitalise.

Testing their mettle against the competition heavyweights was always going to be a massive challenge for West Coast, which fielded 11 players making their finals debut, however he is adamant the experience will hold the club in good stead as they look to keep their season alive next week.

"I've already asked the players to weigh up what they learnt from that game and they have had some great points about that. We will use that to make sure that we know the areas we want to work on to make us better," he said.

In more positive news for the Eagles, Worsfold is confident of regaining star midfielder Daniel Kerr, with the West Coast mentor conceding the 28-year old made it through the Wednesday training session unscathed, however pulled up stiff following a rigorous fitness test on Friday.

"He got so close this week. We don't think the soreness he got out of his fitness test is going to carry over at all. He will be better prepared next week," he said.