Callum Sinclair has taken a while to make his mark at Sydney but put his hand up for a permanent place in John Longmire's best team at the right time of the season with a career-best five goal haul against St Kilda on Saturday night.

Recalled to the Swans' line-up when Sam Reid was forced out of the match with a groin problem, Sinclair kicked five goals from his first ever double-figure haul of 10 marks, eight of those contested, and dominated his dual with highly-rated Saints defender Jake Carlisle in the 42-point win.

Sinclair was dropped when Longmire decided to go with a smaller forward line after Sydney's round 14 win over Essendon, but responded with eight majors, 13 marks, and 46 disposals in his two NEAFL appearances to make sure he was first in line if a spot opened up.

When Reid didn't get up to play the Saints, the 27-year-old former Eagle seized his opportunity to impress.

"When he went out of the team he wasn't playing badly - we just went for a different structure (in the forward line)," Longmire said post-match.

"You need to have that degree of flexibility in your thinking and not get locked into one way of thinking all the time, and to his credit he took that really well.

"He went back and was fantastic in our reserves, has a great attitude, and kept working on his craft.

"He works as hard as anyone on our list and he got some reward for that effort, against (Jake) Carlisle, who is a quality player, and it was a really good night for him.

"He comes and grabs the coaches and tells them what he needs to do, rather than the other way around, and he's really proactive in getting better."

Longmire said he was unsure if Reid would be fit to face Hawthorn next week, but even if he is, Sinclair's outstanding display will force the coach to have another think tank about his set-up inside 50.

In further good news for the Swans, Kurt Tippett matched Sinclair's bag of five goals and 10 marks in the NEAFL curtain-raiser on Saturday night, giving Longmire another headache at the selection table in the run to the finals.

"I thought he (Tippett) played pretty well, he moved well, and marked the ball really cleanly," the coach said.

"He looked a real threat in the air whenever the ball went forward and he finished off the game pretty strongly, so it was good for him."