UPDATED: An injury to Matt de Boer could open the door for Colin Sylvia to finally get a Fremantle call-up.
De Boer left training early yesterday and the club now believes he could be sidelined for up to four weeks.
But Sylvia could be a "real weapon" in the second half of the season if he is given a run exclusively as a forward, according to Essendon great Tim Watson.
Sylvia has failed to live up to expectations this season after being lured west from Melbourne on a three-year deal.
Fitness, injuries and disciplinary issues have conspired to keep him out of AFL selection.
The 28-year-old was used in the midfield during his first five WAFL games with varying degrees of success but was one of Peel's best in their drought-breaking win over South Fremantle, playing in the forward line.
He kicked three goals from 15 disposals and nine marks in the 24-point win, adding six tackles in a performance Thunder coach Cam Shepherd rated as his best this year.
With forward Michael Walters (ankle) sidelined until at least round 18, the Dockers will need someone to step up in the goal-kicking department.
Though Sylvia is far from a guaranteed selection this week, Watson said he had the potential to thrive in the forward line if given a chance.
"What you want in your forward line is blokes who can chase and tackle and do all that stuff," he said.
"But you still want blokes who can turn a half chance into a goal-scoring opportunity.
"Colin Sylvia can do that."
Sylvia's talent in front of goals was on show many times in his 10 seasons with the Demons.
He kicked 129 goals in 157 games, including two bags of five.
Watson said all Sylvia needed to do was improve his work rate.
He said the No.3 draft pick could address that issue with the help of Dockers coach Ross Lyon.
"He doesn't have blistering speed like a Walters," Watson said.
"Walters is really clever and quick and agile and all those things you want in a small forward.
"He doesn't have that, but Ross has been a genius over the years at being able to pick somebody, develop a role for them and get them to play that role. Out of necessity they'll probably have to push this bloke as hard as they can to try and get him to be what they want him to be."