Jack missed all of the JLT Community Series but returned for Sydney’s Round 1 match against Port Adelaide to bolster the Swans’ injury-depleted side.

The Swans have lost their opening five matches in their worst start to a season in more than 25 years.

Coach John Longmire told Fox Footy Jack has been battling an injury since the pre-season.

“Kieren was one of the players who had a good pre-season but got injured just before he was due to play in the JLT series – with a crook hip – and wasn’t able to get any games under his belt,” Longmire said.

“We’ve been playing him now for five weeks and it’s not getting better, it’s getting worse, so he needs at least a couple of weeks off.

“Hopefully some rest and recovery over the next few weeks will get him back into good form and get him fit and firing for the rest of the season.”

The Swans take on Carlton on Saturday in a Round 6 clash at the MCG.