AUCKLAND, NEW ZEALAND - MARCH 16: Adam Keighran of the Warriors scores a try during the round 1 NRL match between the New Zealand Warriors and the Canterbury Bulldogs at Mt Smart Stadium on March 16, 2019 in Auckland, New Zealand. (Photo by Phil Walter/2019 Getty Images)

The injuries keep piling up at the Warriors, with playmaker Adam Keighran the latest to go down with a knee issue.

The 23-year old suffered the injury at training at Tamworth on Monday night and will undergo surgery later this week. He faces an extended stint on the sidelines.

Kodi Nikorima confirmed the unfortunate news to reporters on Tuesday.

"Last night, [Keighran] went down with a knee injury, we're not too sure the full extent of the injury, we'll find out later this afternoon," Nikorima said.

"I think he's going for a scan this afternoon so we'll know more about that tonight."

Nikorima added that Keighran was in great shape upon returning to training.

"Adam was training out in the centres, he came back in really good shape," Nikorima added.

"The first day we came back, we had the bronco test and we actually had eight or nine PBs and he was one of them.

"He was training really well and it was very unfortunate that he went down with an injury last night.

"We're not light on outside backs, thank God, like we are in the forwards but there's another opportunity for someone else to step in that role."

Keighran has made seven NRL appearances for the Warriors after making his debut in Round 1 of last season.