Didier Drogba, Frank Lampard, Michael Ballack and Ricardo Carvalho will all be missing from Mourinho's roster for the Tuesday clash, but the Portuguese believes the team has no option but to win.

"When you have Drogba, Lampard, Ballack and Carvalho you are speaking about 40 per cent of the team. You are speaking about the spine of the team," said Mourinho.

"When you speak about Drogba and Lampard, maybe you are speaking about more than 50 per cent of the goals the team scores, but that's the reality. I don't want to cry on it, I want to work with the players I have available.

"We must win, after that I will say we must win at the weekend and after the weekend I will say we must win against Hull for the Carling Cup and that's the way I approach my season, game after game, competition after competition."

Despite being firm favorites in Group B to reach the last 16 phase, Mourinho conceded that his team will not face an easy job on their way to the next stage.

"I don't think the draw was great for Chelsea, the group is not a better group than last season, but I believe in my team, that we have a team to go through."

Group minnows

On the other hand, Rosenborg coach Knut Torum is aware that his Norwegian side will face an uphill battle in order to go through from a group including the likes of Chelsea, Valencia and Schalke.

"We have to take away Chelsea's strength, speed and power which is at a higher level than we normally face in Norway, but at the same time carry out our own attacks so we don't just allow Chelsea to keep coming at us," said Torum.

"But the group is so strong it will be very difficult for us to go through."