Surgery on Zac Dawson’s broken thumb was successful, according to senior coach Ross Lyon.

Dawson broke his thumb playing for Peel Thunder on Saturday in his first game this season after overcoming a prolonged groin injury.

“Surgery went really well yesterday,” Lyon said on Wednesday.

“Zac is recovering, he’s off today.”

Dawson could miss up to eight weeks with the injury.

It puts pressure on Fremantle’s tall defensive stocks, with Alex Silvagni still sidelined with a hamstring injury for six to eight weeks.