Manchester City manager Manuel Pellegrini accused his players of complacency after their surprising 2-1 home FA Cup quarterfinal loss to holder Wigan on Sunday.

City's dreams of an unprecedented treble - or at least a domestic treble - were buoyed by collecting the League Cup title at Wembley against Sunderland last week.

But against Championship side Wigan, managed by former City player Uwe Rosler and which beat it in last year's final, City found itself down 2-0 after an hour on goals by Jordi Gomez and James Perch before Samir Nasri tallied to give it hope of forcing a replay.

"I think maybe it was the worst effort we have had here in a year," said Pellegrini.

"We didn't have the pace to play against a team that is in a very good moment.

"We knew before the match we were going to play against a difficult team but maybe we thought it was not so difficult. When we finally reacted it was too late.

"We finished one trophy and we won that. Now we have to continue playing in the Champions League and the Premier League, we have a lot of things to fight for between now and the end of the season.

"First we must try to win in Barcelona, then try to continue and reach the top of the table with the three games we have in hand."

City visits Spain on Wednesday in the return leg of the Champions League last 16, although the 2-0 home deficit it carries with it makes advancement a tall order, regardless of the poor showing against Wigan.

"It's a game we lost 2-0 so it's a difficult game," said the City manager.

"We must react tomorrow morning with the responsibility for what happened today - but with a lot of trust about what we can do in the future. We will try to play a good game there and see what happens."

One eye on Barca?

Pellegrini denied he left regular starters Joe Hart, Vincent Kompany and Aleksandar Kolarov on the bench against Wigan with one eye on the Barcelona game, although that was an obvious conclusion to reach.

"No, I didn't leave them on the bench because we have to play Barcelona," said Pellegrini.

"They didn't play today because we are always making rotations in the cup and Premier League and also because they played for 90 minutes for their national teams on Wednesday. It was important for them to have a rest."

Despite the appalling display over the first hour, Pellegrini denied he felt his players had let him down in such a vital contest.

"We all work together, we all have responsibility to win," he said. "It was a special week after winning the League Cup and some international games, but I think all of us have some responsibility."

Not surprisingly, Rosler, who earned cult hero status at City during a four-year career that featured over 150 appearances, ranked the victory as his greatest achievement in management as he looked ahead to a Wembley semifinal meeting with Arsenal.

"Since I've been in the UK I've had very good results with Brentford, building up a club that's winning promotion," he said.

"I have had some highs and some lows, but in general I think coming here against one of the best teams in the world and to win in the way we did, yes, that's my biggest achievement as manager.

"This club has been very respectful to me, and the reception I got was tremendous. I also felt I was very respectful and didn't celebrate after the win. I shook hands and walked in.

"If you ask any young manager who wants to climb up the ladder if he wants to manage against Arsenal at Wembley, of course you take it."