Brisbane Lions coach Chris Fagan is set to undergo surgery after suffering a hamstring injury during the Big Freeze 4 at the MCG on Monday.

Fagan, who went down the slide along with the other 17 AFL coaches in order to help Neale Daniher's fight against MND, tripped and fell as he exited the pool, rupturing his hamstring in the process.

The Lions coach had scans on Monday afternoon, and will now undergo surgery to repair the injury.

With Brisbane having the bye this weekend, it's unlikely Fagan will miss any games while he recovers.