PREMIERSHIP stars Jeremy McGovern and Liam Ryan face Saturday tests to prove their fitness for West Coast's clash with Carlton on Sunday.
McGovern is aiming to play for the first time since fracturing his thumb in the Western Derby on July 19 and is yet to fully exert himself at training.
Ryan is dealing with hamstring tightness stemming from Saturday night's win over Geelong and underwent scans that revealed no significant tear.
"(It's) a concern, but not major, nothing came back on the scan," Simpson said of his small forward.
"He didn't train, but he ran (today)... he got to 30km/h on his running, so he ticked that off.
"He'll be another one we get to captain's run and see how he's going and make a decision then.
"Both of those guys (Ryan and McGovern) had a positive day and for this time of week we're quite buoyant about it but that doesn't make it a lock."
Should Ryan miss, uncapped rookie Nic Reid is in the frame to make his debut after fellow small forward Jamaine Jones suffered yet another hamstring setback at training.
Midfielder Brayden Ainsworth may be asked to push into a forward role with Jack Redden likely to return after missing the win against the Cats with a minor quad injury.
Last week's debutant Harry Edwards has passed his cognitive test after he was concussed but is unlikely to play which could open the door for Josh Rotham or Will Schofield if McGovern misses a third consecutive game.
Tagger Mark Hutchings is available for the first time after a persistent knee injury dogged his shutdown period but will instead play in a scratch match against the Blues' reserves.
Defender Lewis Jetta is also expected to miss his fifth straight match despite adhering to Simpson's demands to improve his fitness after he was dumped following round four.