NASHVILLE, Tenn. (AP) -Nashville Predators center Jason Arnott is expected to miss up to six weeks because of a knee injury.

The team also placed defenseman Mikko Lehtonen on injured reserve with a concussion. The Predators recalled forward Alexander Radulov, the team's 2004 first-round draft pick, from Milwaukee of the American Hockey League.

Arnott, fourth on the team with 16 points, will undergo arthroscopic surgery on his right knee Wednesday. He was hurt in Monday's 3-1 win over Columbus.

The Predators are also expected to be without forward Josef Vasicek on Wednesday against Dallas because of back spasms.