De Gea: United must improve against Barca

David De Gea issued a rallying cry ahead of Manchester United's Champions League quarterfinal second leg at Barcelona.

Manchester United goalkeeper David de Gea warned the Red Devils must improve against Barcelona in the Champions League.

United travel to Barcelona on Tuesday trailing 1-0 in the quarterfinal tie and struggling for form following their underwhelming Premier League victory against West Ham.

Ole Gunnar Solskjaer's United – who had lost four of their past five games prior to Saturday's fixture – needed a late Paul Pogba penalty to see off West Ham 2-1 at old Trafford.

And De Gea issued a rallying cry ahead of the Camp Nou blockbuster after United failed to register a shot on target at home to Barca in the opening leg.

"Of course it's difficult, but if you want to be a top team you have to play big Champions League games, and the weekend after it's the Premier League," De Gea said.

"So you have to be focused and ready for a difficult game again. I think we didn't play well [against West Ham], we have to improve a lot and now we have a big challenge on Tuesday.

"We will try to fight and win the game. We can go with more confidence after the three points.

"It's a big challenge, a special occasion, in Spain, against Barcelona, a Champions League night, so it's going to be an amazing game.

"We're happy with the win, but at the same time we have to improve a lot."