Heckenberg underwent cartilage repair surgery on the same shoulder in June 2007 and subsequently sat out the rest of the season.

This injury follows the sidelining of fellow forward Louie McCarthy-Scarsbrook for up to four months with a broken wrist that was sustained in Friday night's game at Headingley.

Harlequins Rugby League Head Coach Brian McDermott commented:

'We always knew it was coming.'

'Every club gets an injury crisis and it's now up to our young players to step up to the mark and take their opportunity to show us what they can do.'

Harlequins have also been without Stand Off Scott Hill for the last three games due to a knee injury. Henry Paul and Matt Gafa also missed the trip to Leeds, Paul out with a bicep injury and Gafa a hamstring strain.

It is hoped the three players will be back on board for this Friday's game against Catalans Dragons.