Starting with Manchester United, I think people have put a gloss on their result in Rome because they went down to 10 men after just half an hour. It was a flaccid performance that puts qualification in jeopardy. Right from the start they looked below-par and particularly shaky at the back. It didn't help that three first-choice defenders were out. Nemanja Vidic is going to be a big loss because he seems to be the player they've been missing over the last few seasons.

An aggressive, dominant centre-back, even Rio Ferdinand looks much more comfortable beside him. Stepping in for him, Wes Brown looked nervous, as did John O'Shea at right-back. On the left, Patrice Evra's a better fullback than Gabriel Heinze, although Heinze has had that bad injury and maybe needs more time. Up against a Roma attack that seems to lack a potent finisher, they still encountered a lot of problems. Now Roma will be doing what they do best, counter-attacking, as United must chase the game.

Paul Scholes would have been crucial to that but he's out now. His performance in that first half-hour was really difficult to understand.

Normally, he's so reliable in possession but his passing was so wasteful. He also seemed to have this deathwish to get sent off, making silly tackles from the start.

For a player with his experience, who has been so outstanding this season, it's really hard to fathom. His absence is a big blow and means responsibility falls on Wayne Rooney and Cristiano Ronaldo to open up Roma.

Rooney's had criticism this year and his form has been up and down. Some games you think he's turned a corner, the next you wonder why he's playing so badly. That goal will do him no harm though.

He took it brilliantly and it was the move of the match.

Ronaldo did what he should be doing more often, using his pace, going past people and making the pass at the right time. It was a perfect delivery then from Ole Gunnar Solskjaer and Rooney showed great composure.

They'll need to do more of the same on Tuesday.

We're coming to the business end of the season and this is where you're looking for big performances from your big players. Rooney's done it before but Ronaldo hasn't.

People are touting him as the best player in the world but, for me that's way off the mark. He hasn't done it in the big games, the World Cup, the European Championships, the Champions League. He has been very impressive in the league this year but that's against the Middlesbroughs and Boltons.

It's time to do it where the true greats do, like the quarter-finals of the Champions League. United's performance in Rome has put him in a position where he'll have to and it's going to be difficult.

The other English team in jeopardy, Chelsea, were at least in a pulsating game and I expect the return to be every bit as entertaining. It could well develop into a physical battle. When Jose Mourinho's sides have been on the verge of elimination before they've resorted to bad behaviour and petulance and this looks to be following a similar trend.

Physical tactics have worked for Chelsea against a lot of Premiership sides and Europe's lesser lights but Valencia aren't a team you're going to bully. Their one weak point is the keeper, Santiago Canizares. He didn't look sharp at set-pieces and was certainly at fault for Didier Drogba's goal. That might be an area Chelsea can capitalise on.

One thing you can be sure of too, Chelsea won't be intimidated by the Mestalla crowd. I was there before when Arsenal got knocked out in the 2001 quarter-finals and it really is a cauldron.

But I don't think Chelsea are going to be affected by that.

Mourinho has instilled a great team spirit and an incredibly focused will to win.

However, Chelsea are at their best when they're in the lead and can defend things. Now, the boot's on the other foot and I'm not too sure character's going to be enough.

Valencia won't be outfought and are good enough to get the 0-0 draw they need.

Remember, that's exactly what they did to Inter Milan.

As for the other Milan side, AC, it could be the end of the road. Bayern have the right mix of experience and youth which the returning Ottmar Hitzfeld has moulded together perfectly. He's also restored a winning mentality and they've probably done enough in the first round. At Milan, players like Paulo Maldini and Clarence Seedorf have aged badly and the signings they've made have hardly rejuvenated the side.

Finally, Liverpool were very proficient and professional in Eindhoven and a semi-final place is a given.

Rafael Benitez has said he thinks he's got a better side than the one that won it and I would agree. Javier Mascherano's been an excellent addition and Benitez knows how to utilise him in the manner West Ham didn't.

No matter who they get in the semi-final, Valencia or Chelsea, he'll have them in good shape.

They could be the only English side there though as, to join them, Manchester United will need Rooney on top form and Ronaldo living up to a tag he doesn't deserve while Chelsea will have to execute their set-pieces perfectly.

There's work to be done to ensure three English clubs stay in the competition.