Zach Bogosian is sidelined indefinitely with a broken left leg. ((Mike Zarrilli/Getty Images))

Atlanta Thrashers rookie defenceman Zach Bogosian will be sidelined indefinitely because of a broken left leg.

Bogosian, 18, suffered the injury when he was slammed into the boards by rookie forward Darroll Powe in Tuesday's 7-0 loss to the Philadelphia Flyers.

He will not require surgery.

Bogosian has played eight games for the Thrashers, posting a minus-2 rating with 13 penalty minutes.

He was selected third overall in the NHL draft on June 20.

With files from the Associated Press