West Coast's injury list has reached crisis point after Dom Sheed and Brendon Ah Chee became the latest players to join the casualty ward.
Sheed (hamstring) and Ah Chee (finger) will miss Thursday night's crunch clash with St Kilda at the Gabba.
Defender Lewis Jetta (calf), Jack Redden (fractured thumb) and Mark Hutchings (hamstring) were also ruled out earlier this week, joining premiership stars Luke Shuey (hamstrings) and Elliot Yeo (osteitis pubis) on the sidelines.
It means West Coast will enter their match against St Kilda missing five premiership midfielders.
Defensive trio Liam Duggan, Tom Cole and Jackson Nelson are the obvious choices to get more midfield time to help fill the void, while the Eagles will hand a debut to 22-year-old onballer Hamish Brayshaw.
The Eagles have been boosted by the return of ruckman Nic Naitanui and Shannon Hurn, while Will Schofield, Jack Petruccelle and Jarrod Brander have also been recalled among six changes.
Sheed, Yeo and Ah Chee could return for next week's final-round clash with North Melbourne.
But Redden will miss at least three weeks after undergoing thumb surgery while Shuey, Jetta and Hutchings face a race to be fit for the start of the finals.
Simpson said the club's injury woes will not be used as an excuse.
"There's probably seven or eight out of our starting 18, but we're still excited," he said.
"We've always been a role-driven side that plays on system.
"We want talent in our side, and we're going to be without a bit of our A-grade players. But that doesn't mean we can't win or can't play with that spirit we've been talking about.
"Our boys look at it as an opportunity. It's a really big game. It's an opportunity to play finals. The Saints are right behind us on the ladder. We're not rolling over, that's for sure."
Tom Hickey was dropped to make way for Naitanui.
The Saints recalled Max King, Tim Membrey and Nick Hind with Ryan Abbott, Ed Phillips and Jonathon Marsh making way.
West Coast (10-5), sitting fifth, will probably need to win their remaining two games to have a chance of snaring a top-four berth.
St Kilda (9-6) are in sixth spot and are aiming to secure their first finals berth since 2011.
The injury-ravaged Eagles received one dose of good news on Wednesday when it was confirmed star goalsneak Liam Ryan had re-signed for a further two years, tying him to the club until the end of 2022.
Ryan is in line to receive his first All-Australian honours in 2020 after booting 21 goals from 14 games this season.