WEST Coast livewire Willie Rioli is facing up to three months on the sidelines after confirmation he will undergo surgery on his damaged hamstring tendon.

The mature-age draftee injured his right hamstring last week and, despite jogging around the boundary and kicking at training on Monday, he is set to go under the knife.

Rioli had been a shining light on the training track this pre-season with his speed and forward pressure, and was set for a club debut against Greater Western Sydney in the JLT Community Series on Saturday.

But the exciting 21-year-old, who shed 16kg before the 2016 SANFL season, will now be out of action for 10-12 weeks.

In better news for the Eagles, forward Simon Tunbridge ran for the first time on Monday after undergoing a hybrid LARS operation on his ruptured anterior cruciate ligament in December.

"It was a bit weird, I just didn’t have confidence running and putting weight through the knee, but once I got going it felt good and I couldn't wipe the smile off my face," Tunbridge told westcoasteagles.com.au.

Tunbridge, who was demoted to the rookie list at the end of last year, underwent the radical LARS hybrid option in a bid to get back on the park midway through this season.

The 23-year-old will soon overtake Nic Naitanui in his ACL rehabilitation after the star ruckman had a traditional full knee reconstruction last August.

"I kind of feel bad for him. I had my surgery four months after him and now I'm overtaking him and hopefully training in a few weeks," Tunbridge said.