Schalke 04 striker Raul insists his side can overturn the 2-0 deficit following the one-sided first leg of its Champions League semifinal with Manchester United.

The former Real Madrid great was unable to add to his competition record 71 goals in Tuesday's game at Veltins Arena, as United took a sizeable step towards the May 28 final with a dominant attacking performance.

Despite United's advantage, however, Raul refused to give up hope of an unlikely comeback.

"In the return leg, anything is possible," he said.

"You don't know what could happen. A penalty for us, a sending off for them, nothing is impossible in football."

United left Gelsenkirchen in prime position in the tie thanks to rapid-fire goals in the 67th and 69th minutes from Ryan Giggs and Wayne Rooney.

Only the excellence of home goalkeeper Manuel Neuer kept Schalke in the game in the first half and Raul, a Champions League winner with Real in 1998, 2000 and 2002, acknowleged that United had been a class apart.

"We were hoping for another result, another outcome in the match, but we're happy all the same because we played at our level," he said.

"The problem was that Manchester United were at another level.

"The only regret is that we didn't create enough chances and we conceded two goals in two minutes.

"Getting to the semifinals is a source of great pride for the club and the supporters. We tried everything and the fans realized, because they applauded us warmly after the match."

Raul, 33, joined Schalke from Real last summer and has become the emblem of its unlikely Champions League charge, having scored in both legs of the sensational 7-3 aggregate defeat of holder Inter Milan in the quarterfinals.

But with Schalke in 10th place in the Bundesliga, well below the Champions League qualification places, next Wednesday's return leg at Old Trafford could prove to be his final game in a competition that he has graced like few others.

"Finishing at Old Trafford wouldn't be too bad," he said.

"We want to finish by not giving up lightly and offering a good image of ourselves against a great team in a great stadium and with a wonderful atmosphere."

Raul's contract is due to expire in 2012, but he revealed he could decide to extend his stint with the side from the Ruhr.