ST KILDA coach Ross Lyon says he will refuse to play his star players in the NAB Cup if they are not fully fit.

Luke Ball, Lenny Hayes, Nick Riewoldt, Sam Gilbert and Jason Gram all stood aside as the Saints defeated Richmond in round one of the NAB Cup at Telstra Dome on Friday night.

But Lyon says there is no point throwing his big names into the mix if they are managing niggling injuries, which he said was the case for Riewoldt.

“I can tell you bona fide there is no ACL injury [to Riewoldt],” Lyon said.

“He has got a slight impingement and we have had it investigated because he is a very important player.

“It hasn’t quite settled since Christmas the way we wanted it to so therefore you continue to investigate it because it is unacceptable after four months off to go into round one at 98 per cent.”

Lyon said the hit out provided his young side with some much needed experience on the big stage.

“It’s great to be on a great surface and a great stadium in front of a big crowd but we are not going to take unnecessary risks to players who aren’t ready to play,” he said.

But as the big St Kilda names sat out the NAB Cup opener, some of the lesser lights stepped up, notably Clint Jones, who had 21 disposals.

Lyon said Jones had shown signs he would improve in his second year at AFL level after being drafted from Western Australia.

“It’s a big step from the WAFL to AFL footy,” Lyon said.

“In the WAFL you run around chase the ball and you don’t worry about your opponent too much and he did that very well.

“But in the AFL, most systems ask you to play both sides of the ball and he struggled with that but we feel he is coming to grips with it.”

One big name Saint who didn’t miss was veteran Robert Harvey, who performed well in the first match of his 21st season of league football.

Lyon said he never thought about giving the 36-year-old the week off.

“I’d love to say; 'Rob, you don’t have to play or train because you’ve won two Brownlows and played 300 games',”  Lyon said.

“We’ll manage his game time obviously but you can’t hide him from the work in the AFL. At some point you’ll have to do it.

“You have to expose them to the workload.”

Gram, Gilbert and possibly Leigh Fisher will return for next week’s game at Manuka Oval against the winner of Geelong and Melbourne.