DAVID Armitage nearly proved his fitness for St Kilda's clash with the Brisbane Lions on Sunday, but the senior midfielder remains no certainty to return in round four against Collingwood.

Armitage missed the Saints' round two loss to West Coast after suffering a groin injury in the season opener against Melbourne.

The 28-year-old trained this week in a bid to play against the Lions, but Saints coach Alan Richardson said the on-baller faced at least another round on the sidelines.

"He was close (to playing against the Lions)," Richardson told reporters on Friday.

"Dave trained reasonably strongly on Thursday, but didn't quite pull up the way that we would like.

"So it looks like it will be at least another week for Dave."

There was better news at selection for another veteran Saint injured in round one, with former skipper Nick Riewoldt cleared to return from a knee injury.

Things looked bleak for Riewoldt when he was taken from Etihad Stadium on a motorised cart in round one after hyperextending his right knee late in the loss to Melbourne.

However, initial fears the five-time All Australian had ruptured his ACL proved unfounded as he escaped with nothing more than trauma around the knee joint and bone bruising.

The Saints thought at the time Riewoldt would be sidelined for at least two rounds, but the 17-season forward again demonstrated his remarkable recuperative powers.

"He's a pretty special person like that, he's a very durable, resilient guy that for his whole career really has been able to deal with injury and overcome injury. This is another great example, so we're rapt to have him back in," Richardson said.

"(He) trained really strongly on Thursday, feels really good. We made sure that he did everything that he's going to be asked to do on game day, with respect to contests, jumping and changing direction, all that sort of aggressive lateral movement, and not only was he able to perform strongly but (he) pulled up really impressively (too).

"So he's fine, he's right to go."

The Saints' first pick in last year's NAB AFL Draft, Ben Long, could make his debut on Sunday after being named in St Kilda's 25-man squad.

Long was taken at pick No.25 overall after representing the Allies in last year's NAB AFL Under-18 Championships and starring for Footscray in its run to the VFL premiership.

Richardson gave little away on whether the 19-year-old would be named in St Kilda's final 22 on Friday afternoon.

"He's in the mix. We don't play until Sunday so we've still got a little bit more work to do," the Saints coach said.

"Unfortunately I can't give you the scoop, but he's an exciting player, he's a contest winner, he makes opportunities out of very little.

"He likes to put on pressure, he likes to hunt the opposition, so he'll certainly play some really strong footy for us. Whether it's this week or not, we'll just have to wait and see."