Kangaroos winger Josh Mansour has been ruled out for the remainder of the Four Nations tournament after suffering a knee injury at training on Wednesday.

Scans on Wednesday night confirmed Mansour had suffered an ACL injury.

"It's obviously shattering news for Josh," Kangaroos Coach Mal Meninga said.

"He has been a popular member of the squad and was excellent for us against Scotland last Friday."

Kangaroos medical staff will work with the Panthers on the best treatment options for Mansour.

"Unbelievably bad luck for our man Josh Mansour," Panthers Executive General Manager Phil Gould AM tweeted.

"We will bring him home and get his surgery done ASAP."