Reports on canaries.co.uk say the forward, who has scored twice this season, fell awkwardly and had to be taken from the training pitch on a stretcher. He will definitely miss the weekend's match, but it is unknown for exactly how long the former Crystal Palace and Peterborough man may be sidelined.
The injury is a major blow for Worthington with Darren Huckerby facing a two match suspension following his hissy fit at Stoke and Dean Ashton fighting for fitness. Peter Thorne. signed from Cardiff in the summer, has also had trouble with his knee.
Ironically, the manager had attempted to bring in strikers Clinton Morrison and Francis Jeffers to an area of the team considered to be strong already, but the rotten luck which has seen the Canaries fail to pick up a league win this season looks set to continue.
One possibility for Worthington would be to bring in youngster Ryan Jarvis for the televised clash on Saturday. Jarvis is no stranger to the Sky cameras, having scored a memorable goal against Liverpool last season.