The Spanish keeper has had a torrid first month at Old Trafford, letting in two goals against Manchester City in the Community Shield final, struggling against West Brom’s physical approach and he was at fault for Theo Walcott’s equaliser in the Red Devils’ 8-2 win against Arsenal.
And Fulham shot-stopper Schwarzer has warned the former Atletico Madrid man that the Premier League is a far tougher training ground than La Liga.
He told the Alan Brazil Sports Breakfast show: “That’s the downside of playing for a club like Man United.
“He’s going to have to find his form very, very quickly. It’s going to be a very, very tough school for him.
“The Premier League and Spanish leagues are worlds apart in the type of football that is played.”