Victor Valdes
Valdes is closing in on full fitness ahead of potentially signing a permanent deal with United.Getty Images/Denis Doyle

Spanish goalkeeper Victor Valdes is closing in on earning a permanent deal at Manchester United after continuing his recovery from an anterior cruciate ligament injury.

Valdes is training at United Carrington Training ground and manager Louis van Gaal admitted the club are monitoring the 32-year-old's progress.

The former Barcelona stopper is a free agent after seeing a move to Monaco fall through during the summer transfer window, and can therefore be signed at any stage of the campaign.

And Valdes' return to full fitness has ramped up in recent weeks since beginning training with United, with the three-time Champions League winner writing on Twitter on Sunday: "Great training session Today. Almost Ready! Thanks for your supportive messages throughout these months. They have helped me a lot!"

With David de Gea – arguably United's best player this season during the uncertain start to van Gaal's career – unchallenged in goal for the 20-time English league champions, the Dutch coach could add substantial competition for the No.1 jersey at Old Trafford.

Having won 21 major honours with Barcelona and been part of Spain's squad during their 2010 World Cup and 2012 European Championship victories, Valdes will provide considerable experience behind De Gea, who has been first choice at United since joining from Atletico Madrid.

Spain midfielder Juan Mata says Valdes is yet to make a decision regarding a permanent switch to United but that he has already integrated himself within the club's dressing room.

"Today (for yesterday) I was with him," he told Spanish radio station COPE. "He is training apart from the squad. He is still recovering from the knee injury. But he is very well, eager to be in shape soon. He is not training with the team but he is in the dressing room.

"Will he sign? "I do not know. It depends on the club and how he feels about the knee. But currently he doesn't belong to the team. He trains apart."