OUT-OF-CONTRACT St Kilda ruckman Billy Longer will miss the rest of the season after having ankle surgery on Tuesday.

Meanwhile, star defender Jimmy Webster is set to return from a right groin flare-up for the Saints' clash with the Western Bulldogs at Etihad Stadium on Saturday night.

Longer, 25, has struggled this year and played just five games in the senior side after an injury-interrupted pre-season and St Kilda head physio Andrew Wallis said Longer had been under duress.

"Billy Longer went in for surgery this morning (Tuesday) on his ankle," Wallis told saints.com.au.

"We felt that it was probably hindering his performance a little, so he's gone in for a routine posterior clearance and stabilisation of the lateral ligaments.

"It gives him a really, really good opportunity moving forward to have a solid pre-season, so we're actually quite excited about putting him in early."

Backmen Webster and Logan Austin seem to have overcome their groin issues.

"They'll both have to get through training on Thursday but we expect them to be available for selection," Wallis said.

The VFL team has a bye at the weekend.

Key forward Paddy McCartin is out of his moon boot as he recovers from a Lisfranc sprain in his left foot.

"(McCartin is) starting his formal rehab. He's been fantastic in the off-legs side of things and is really progressing well," Wallis said.

The prospect of Dylan Roberton, who finished second in the 2017 best and fairest, returning from a heart condition next season is improving.

"Good news on Dyl though, he's been running now for about three or four weeks and getting himself in some good shape for the pre-season," Wallis said.

Defender Brandon White missed last week with a hip flexor and will again be unavailable while pressure forward Nathan Wright has started running in his recovery from knee bone bruising and is expected back in about a fortnight.