Manchester United have announced the signing of former Barcelona goalkeeper Victor Valdes on an initial 18-month contract.
Valdes, 32, has impressed manager Louis van Gaal enough in a 10-week training spell with United. Valdes moved to England in October when Van Gaal gave him the chance to continue his rehabilitation from a cruciate ligament injury.
The Manchester United boss confirmed that Valdes joins the club as the No. 2 goalkeeper behind David de Gea.
"I am delighted Victor has signed for the club. Victor is a very experienced goalkeeper and his record speaks for itself," Van Gaal said in a statement on the club's website. "I have said on many occasions that Manchester United will always be interested in the best players.
"Victor has remained very professional throughout his rehabilitation from injury and has been very impressive during his training sessions with the first team over the past weeks.
"He joins the club as the number two goalkeeper and is a great addition to the first team."
The Spain international has not played first-team football for nine months since he was hurt in Barcelona's 3-0 win over Celta Vigo with an injury that forced him to miss the World Cup.
Valdes had already announced his intention to leave the Camp Nou when his contract expired. He made 535 appearances for Barcelona, winning La Liga six times and the Champions League three times.
Valdes said it was an "honour" to sign for United but acknowledged he faces an extremely tough fight to earn a first-team place at Old Trafford.
"I think now, in the moment, [De Gea] is the best goalkeeper in the world," Valdes told MUTV. "His performances every day and in every game shows everybody that his level is very high. He has had a great year and it is very nice."
Valdes does not appear to have any qualms about being De Gea's deputy.
"I am here to help everybody," he said. "Always in my career, I have played to help my team-mates, to help my coach and to help everybody. I am a part of the team and I am not a problem, I am just a part of the team."
On being reunited with Van Gaal, Valdes said: "I would like to thank Louis van Gaal and the club for allowing me to do my rehabilitation and to train with the team at the Aon Training Complex. From my short time here I can already see this is a very special club. I worked with Louis van Gaal during my time at FC Barcelona and to have the opportunity to work with him here at Manchester United is a dream come true."
He will become Van Gaal's seventh signing, after Ander Herrera, Luke Shaw, Marcos Rojo, Angel Di Maria, Daley Blind and Radamel Falcao, and his first of the January transfer window.
His move could also bring an end to the Old Trafford career of Anders Lindegaard, who has been De Gea's deputy, while De Gea himself has been linked to a move to Real Madrid.
United's other two goalkeeping options are 21-year-old Sam Johnstone, who is on loan at Doncaster, and 24-year-old Ben Amos, who was criticised by Van Gaal for letting in Miralem Pjanic's 60-yard lob against Roma in pre-season.