A HELMETED Paddy McCartin will take the field for St Kilda on Saturday afternoon against Richmond at the MCG as he returns from his seventh concussion since the start of 2014.

Saints coach Alan Richardson told reporters on Friday at RSEA Park McCartin performed impressively in the headgear on Thursday.

"He trained with the helmet yesterday. It wasn't a long session, it was a 30-minute session, but he really attacked the footy and played with some real confidence. He'll play with that," Richardson said.

McCartin, 22, has missed the past two matches after suffering the injury against Melbourne.

Whether the key forward wears the helmet long-term is yet to be decided.

"Don't know. It's just something that Paddy has decided to do," Richardson said.

"The reality is all the research suggests that it doesn't help much, but if you were to ask Angus Brayshaw, it didn't do him any harm.

"Nathan Burke, a former champion of our footy club, has spoken to our doctors and said exactly the same thing, that whilst the research doesn't suggest much, that the player feels a bit more confident, and that's pretty important."

Meanwhile, Richardson revealed inside midfielder David Armitage has been dealing with hamstring tendinitis over the past month and is no certainty to line up in the VFL on Sunday.

"He's actually had a bit of hamstring tendon issues. That's been bugging him for about a month now," Richardson said.

"We've still needed to play him, because he's so good in contest and really creative when he gets the ball, but it's really hindered his ability to get from contest to contest.

"You would've seen a couple of ground balls last week that he just wasn't able to get down on. It's just not working for him and working for us, so we needed to make the change."

Two bouts of groin surgery restricted Armitage, 29, last season.

"We've been banged up a little bit and been fielding a really young team. We've had Dave play but he hasn't been at his best," Richardson said.

"He's had a couple of issues, physically. Nothing that a rest will fix, unfortunately. He needs to continue to play and that's my understanding at this stage.

However, Richardson was optimistic Armitage could regain his physical capabilities.

"At the moment, he just hasn't been able to get it done, and I'd expect him to go back and get his body right and be much more explosive in terms of the way he moves. We expect him to get back into the team."

The Queenslander is contracted until the end of 2019.

While the Saints will have more presence in attack with McCartin replacing Rowan Marshall, Mav Weller was concussed and suffered a badly cut lip after clashing heads with Jade Gresham at training on Thursday.

The 26-year-old is no certainty to return against West Coast at Optus Stadium.

"It (concussion) was late in the week so he's no certainty for the following week, but we're hopeful and optimistic," Richardson said.