Wests Tigers NRL playmaker Tim Moltzen has suffered a serious knee injury at a pre-season training session.

Moltzen was writhing in pain and was carried off the training paddock in an ambulance on Thursday.

It’s a devastating blow for Moltzen, who has suffered repeated knee problems throughout his career, including in the season just gone.

The injury couldn’t come at a worse time for the Tigers either, with their playmaking stocks already tested by the departure of Benji Marshall in the off-season.