Sergio Romero has kept three clean sheets in his first three Premier League matches for Manchester United
Louis van Gaal: Man Utd's Sergio Romero not proven yet
Manchester United manager Louis van Gaal says goalkeeper Sergio Romero has yet to prove he can deal with the rigours of the Premier League.
United signed Romero, 28, on a free transfer in July with Van Gaal concerned over David De Gea's focus.
Romero has kept three league clean sheets but when asked if he has proved he can cope with the physical challenge Van Gaal said: "I don't think so.
"Until now we don't allow a lot of shots or moments in our 16-metre area."
De Gea saga 'an absolute joke'
Romero is poised to keep his place in goal for United's trip to Swansea on Sunday while Spain international De Gea, 24, remains the subject of interest from Real Madrid.
Van Gaal, 64, acknowledged that former Sampdoria goalkeeper Romero has made "very good saves" so far.
However, the Dutchman said only a stop in United's 4-0 win away over Club Brugge "was very important" along with one he made in their 1-0 win over Tottenham.
"He could not show what he can show, I think, but that is only a compliment for the team," Van Gaal added.
Romero took a while to adjust
Van Gaal says because Romero only joined United 12 days before the season started it has taken a while to build an understanding with his team-mates.
"The difficulty was the co-operation between the new players and him," Van Gaal said of Romero's first days at the club.
"We have had special training sessions with him. Not only with him and the goalkeeping coach (Frans Hoek) but also the players.
"We have given a lot of attention to that and because of that we could overcome that."
Hernandez can silence his critics
Javier Hernandez has scored 37 Premier League goals in 103 appearances
While the Red Devils have been tight at the back in the Premier League, they have not found scoring goals as easy.
United captain Wayne Rooney eased some of those concerns with a hat-trick in the win over Club Brugge during the week, but fellow striker Javier Hernandez has come under scrutiny after he missed from the penalty spot in the match.
"Every player who plays for Manchester United has to cope with that pressure," Van Gaal said when asked about the Mexico international.
"It is like you (the media) have written down Wayne Rooney into the ground and now he has scored three goals and he is again God."