Louis van Gaal has warned new signing Victor Valdes that it will be very difficult for him to displace David de Gea as Manchester United's first-choice goalkeeper.
The former Barcelona player signed an 18-month contract on Thursday after he impressed Van Gaal during his time training with United.
But although Valdes was first choice at the Nou Camp, his fellow Spaniard De Gea has been in outstanding form this season and is expected to retain his Player of the Year award at Old Trafford.
While Van Gaal does not expect Valdes to enjoy sitting on the bench, he told the 32-year-old that De Gea is established in the team.
"Nobody is happy being No. 2 and he shall have to have ambitions to beat David de Gea but that shall be very hard for him," Van Gaal said in a news conference.
Van Gaal first worked with triple Champions League winner Valdes at the Nou Camp and said the Spain international, who suffered a cruciate ligament injury in March before leaving Barcelona on a free transfer in the summer, had impressed with both his form and fitness.
He added: "When you invited Victor Valdes to have his rehabilitation here in Manchester United you do that for him but also for yourself so I had then the chance to see him in his behaviour in his rehabilitation, but also if his quality is still the same and he has confirmed both. That is very important for me and also for him."
Van Gaal was asked if he wanted to have two of the world's best goalkeepers but replied: "My ambition is to have the best players who can collaborate with each other to form the best team in the world."
United had been criticised in previous transfer windows for struggling to sign and Van Gaal, who refused to be drawn if he will bring in other players, was pleased how fast they acted.
He said: "We were the first who bought a player. We were very quick."