St Kilda veteran Leigh Montagna has admitted he doesn't know when a decision on his future will be made by the Saints.

Montagna will be out of contract at the end of the season, and understands that his 16th year at the Saints could be his last.

"I'm not sure when the decision will come," Montagna told reporters on Tuesday.

"As we understand, it's not my decision anyway.

"The club's going to have a fair influence on that and when that is, that will take care of itself. At the moment, we're just worried about playing good footy."

Despite copping some criticism from former Hawthorn champion Dermeott Brereton last month about his toughness, Montagna has had an impressive 2017 campaign, missing just one game so far this season.

The 33-year-old is still averaging 25.3 disposals and 3.9 tackles a game, and is performing well enough to secure his spot in St Kilda's spot week in, week out.

He isn't getting too ahead of himself however, as the rebounding defender says there's still plenty of football to play this season.

"It is still a bit too early. There's still a lot of the season to play out," Montagna said.

"There's still eight games, plus finals, to go. We're still (in) a precarious position on the ladder, so we just need to continue to worry about trying to win games, and that's where my focus is at."

Montagna joins former captain Nick Riewoldt and defender Sam Gilbert as unrestricted free agents at the end of the season, after Sean Dempster retired earlier in the season after a decade with the Saints.