Daniel Kerr's tight left hamstring will be closely monitored over the coming days, but the mental state of the star West Coast midfielder could be just as important in determining his availability for Saturday's AFL western derby against Fremantle.
Kerr was clearly inhibited in last Sunday's 98-point win over Brisbane, with the 29-year-old tallying just four disposals before being subbed off early in the third quarter.
Although the physical effects of the tight hamstring curbed Kerr's influence, it was also his mindfulness of not making the injury worse that prevented him from hitting full stride.
Subsequent scans ruled out any serious damage to the hamstring, but it did show Kerr suffered bleeding in the area.
Forward Jack Darling was struck down with a similar complaint during the round 16 loss to Sydney, but managed to get up for the following week.
However, even if Kerr is physically cleared to play this week, the 2007 All-Australian might be given the week off anyway after coach John Worsfold revealed the tight hamstring had played on Kerr's mind against the Lions.
Kerr missed most of the 2010 season after tearing the hamstring off his bone in his opposite leg.
"Kerrey said he was tight from the very start of the game. He didn't really want to open up and hit any sort of speed. He was a bit concerned," Worsfold said on Wednesday.
"He's got a history of how his hamstrings feel prior to doing his really bad injury a few years ago. That was playing on his mind from the very start of the game.
"He was basically pacing himself until he got to the point where he didn't want to take the risk anymore."
Kerr and ruckman Dean Cox (ankle) were set to be put through their paces at Wednesday's closed training session.
Cox is recovering well from his ankle complaint and is considered a better chance than Kerr to play against the Dockers in a match that is pivotal to West Coast's top-four chances.
Worsfold said Mitch Brown, Jacob Brennan and Ash Smith were all in line to replace suspended skipper Darren Glass, while Tom Swift could come in if Kerr is ruled out.
The Dockers have lost their past three matches against West Coast, and are desperate to make up for their embarrassing round nine display when they kicked just five goals in a 48-point loss to their arch rivals.