Watts is the third Plymouth Argyle player to be ruled out with a long-term injury this season – winger Xavier Amaechi is out with a similar injury to Watts, while defender Julio Pleguezuelo has undergone knee surgery.

Defender Jack Mackenzie is still out with a problem picked up in pre-season while goalkeeper Conor Hazard is returning from a knee problem sustained while on international duty in June.

Jamie Paterson and Kornel Szucs are also currently sidelined with injuries.

Cleverley says he and the club are undertaking a review into the volume of injuries players have suffered this season.

It is the second successive season the Pilgrims have suffered major issues early in the campaign, with former boss Wayne Rooney saying he would undertake a similar review last November.

“We’ve done a large bulk of it now to try and come to the reasons why.

“I think those things should be kept in-house and all we can look to do is rehab those guys the best we can and, really importantly, make sure that we set out the right measures so that our injury record improves and we prevent any further injuries.

“We’re doing everything we can, the players also need to make sure that they’re in the best condition to perform at this level consistently and we should get better.”