While West Coast comfortably cruised past the Hawks, they did so with Yeo as a late withdrawal with groin soreness, with the diagnosis now ruling out their midfielder for over a month.
The latter was hospitalised with an apparent compartment syndrome after sustaining a cork in the club’s scratch match with Hawthorn on Sunday.
Simpsons revealed Yeo’s injury was well know ahead of the round 12 clash, with the club taking every precaution.
“He got a little bit tight last week and we didn’t know how he would recover, so we gave him until today,” he said.
“It might be an osteitis type of issue, so we were hoping it wasn’t. It just hasn’t pulled up well, so he might be out for a few weeks, which might mean five games.”
The Eagles now look ahead to playing their next five games in 19 days, with match-ups against the Giants, Tigers, Bombers, Bulldogs and Saints.
West Coast are fixtured to play North Melbourne in round 18 to end the home and away season.
Touching on Vardy’s prognosis, Simpson said Vardy’s latest setback could cost the Eagle his season.