Rafael Benitez, the Liverpool manager, says the referee must be strong during tomorrow night's Champions League semi-final, second leg with Chelsea.

Roberto Rossetti, an Italian referee, will take charge of the match at Stamford Bridge and Benitez says he is worried by his track record. Of the five Champions League matches Rossetti has taken charge of this season, all but one has ended in home wins, the exception coming in Chelsea's win over Valencia in Spain in October.

"In the last six games in Europe he has refereed, five times the local team have won and once they haven't," Benitez said. "That was Valencia against Chelsea - it's very curious. "If he knows he must be strong, that is okay."

Following John Arne Riise's 94th-minute own goal at Anfield the tie is delicatley poised at 1-1, but despite critising Konrad Plautz, the referee at Anfield, for allowing so much added time in the first leg, Benitez says all the matters is reaching the final.

"I'm not bothered about how I'm judged - I'm more bothered about how we progress in the competition. We have focus and now we are trying to go to the final. We must do the right things."