ST KILDA is confident full-forward Fraser Gehrig will be ready for round one, after Gehrig injured his calf during Saturday's five-point NAB Cup win over Geelong at Manuka Oval.

Gehrig appeared hurt after setting himself for a marking contest, before pulling out at the last minute.

Speaking post-match, coach Ross Lyon said Gehrig's setback needed to be assessed fully before a definite answer could be given.

"It looks like he's maybe just strained a calf, so it's not ideal, but it won't affect him you wouldn't think for round one," Lyon said.

"We've got to assess. It was a hot day [with] limited interchanges."

Key forward Justin Koschitzke kicked five goals in an outstanding performance for the Saints, but left the ground with the game in balance in the final term. Lyon said Koschitzke had simply been rested.

"We couldn't risk it," Lyon said.

Lyon was also pleased for first year Saint Jack Steven, who booted the winning goal late in the match. 

"We all like kicking goals, so if you pick it up from 10 metres out, they're not too hard to kick those," Lyon said.

"It's nice for the kid. He's training hard and he comes from a good family and he's doing his VCE, so he's happy."

As for the prospect of a semi-final against Essendon at Telstra Dome next week, Lyon remained pragmatic about his side's pre-season campaign.

"We were exposing our list and we preferred our younger players stood up again,” Lyon said. “[Geelong] had a young group in again and it was really hard fought. At the end of the day you need a bit of luck. We got a little bit of luck and you move on to the semi-final.

"It means we're through to the third week and we can build for round one a little bit more and we don't fly, so that's a win, because I think [if we’d lost] we would have been off to the Gold Coast."