Star defender Jeremy McGovern will undergo scans to determine the severity of a groin injury after he was removed from the RAC Derby in the third quarter. 

The injury struck shortly after the Eagles had substituted key defender Harry Edwards in an effort to spark their game and try something different. 

Coach Andrew McQualter said the decision to move star forward Allen into defence as a result was something he had previously spoken to the co-captain about. 

"We knew we were slightly thin with key backs, but he's played a little bit of key back in his career as well, so it's an option and we'll just have to see where it goes with match-ups and who we're playing," McQualter said. 

"We understood we had to sub [McGovern] out straight away, so there's clearly something in it. 

"It's funny how the world works. You [sub out] one key back, the other one gets injured. That's unreal, right?"

The Eagles also shifted young star Harley Reid to half-back after a challenging game in the midfield, with McQualter keen to build the No.1 pick's ability to play multiple roles.  

"He was getting some attention from (Matthew) Johnson, so we just thought at that time the game needed something different … and the last 20 minutes of the game, I think we did see something that we liked," the coach said.  

"I think if we can add another string to his bow, he can become a pretty dangerous player down there as well.

"Not many young players play AFL midfield straight away, it's a hard task. Most midfielders are really senior guys that have been playing it for a long time. 

"We want to be able to be flexible and play multiple roles. So I think it's something we'll keep exploring."