Jack, who comes off contract at the end of this season like fellow veteran Jarrad McVeigh, has played four AFL games during an injury-marred 2019.

The 32-year-old's most recent setback was a hip problem but he has since returned, playing two matches in the NEAFL.

"He's like any player, you want him to come in and impact. We don't want him to just come in, tick the box," Longmire said.

"He's got a bit more footy under his belt but we were happy with what Ben Ronke did on the weekend, (while) James Rowbottom has played a couple of games at AFL level and showed some real potential."

Longmire praised Jack's team-first attitude, which has been on display while mentoring teammates in the seconds.

"Rowbottom spoke about it during the week to me. How good it was having Kieren involved in the reserves, talking to him during the game," Longmire said.

"Then he (Rowbottom) was able to come up to senior footy and hold his own.

"That's quality leadership from Kieren, helping a younger player out who could potentially be taking his spot and be OK with that. That's the sort of club we want to be."

Veteran Swans defender Heath Grundy has already retired this year, while Nick Smith may be forced to do the same because of a recurring hamstring injury.

Longmire suggested it's too early to speculate whether Jack and McVeigh will play on in 2020 or not.

"That'll unfold. That takes care of itself usually, that evolves," he said.

McVeigh is back training and could return from a hamstring injury against Essendon at the MCG on Saturday, but Longmire cautioned the star had "only played one and a half games in a 13-week block".

Longmire continued to be evasive regarding the vacant coaching job at North Melbourne, who have made it clear they're keen to headhunt the 2012 premiership coach.

"I'm not talking about it. The club's not talking about it, we don't talk about it," he said.

Longmire is contracted to coach the Swans until the end of 2020 season but could potentially ask for an early release.

Australian Associated Press