Manchester United's door to the second phase of the Champions League may have creaked open like a rusty old gate but at Old Trafford tonight, having already extended their luck to breaking point, they will attempt to prove that their presence is no fluke.

Panathinaikos will provide the opening examination for United in Group A and, after watching his team stagger somewhat unconvincingly to this juncture, the message from Alex Ferguson was unmistakable last night: it is time to get serious.

United have already lost twice in Europe this season, against PSV Eindhoven and Anderlecht, and had it not been for the skewwhiff finishing of Dynamo Kiev's strikers 13 days ago, the 1999 European champions would be trying to digest the wholly unpalatable diet of UEFA Cup football.

For Ferguson it has left a smouldering sense of irritation. His team may have fine-tuned a talent for living on the edge but the United manager cannot avoid feeling that if they keep opting for the high wire they will eventually overbalance.

"We always seem to make things harder than necessary," he said yesterday. "We want to do a lot better than the first phase and, in fairness to the players, I think they will do a lot better. They realise this is the real thing now."

Ferguson believes 10 points should be enough to see the Premiership champions emerge from a group that also incorporates Valencia and Sturm Graz, both of whom United beat last season.

Then, if his early thinking goes according to plan, things will really get interesting. "With the exception of Barcelona, all the usual suspects are still there. We are capable of handling our group, I think Arsenal should qualify and Leeds might well be the surprise package; being in a tough group will be no handicap to them because the other teams might cut each other's throats," he said. "The Spanish did it last time, with three teams reaching the last four. Who knows, maybe this could be England's year."

First things first, however, and Panathinaikos have already shown little respect for reputations, having beaten Hamburg in Germany and drawn with Juventus at the Stadio delle Alpi as well as beating the Italians 3-1 at home.

The 18-times Greek champions rely on their international striker Nikolaos Liberopoulos, last season's leading scorer in the first division, but their counter-attacking game is based on a sound defensive unit.

"Knocking out Juventus is no easy route to this stage, so we know what we're up against and we will have a lot of respect for them," said Ferguson. "They don't score many goals but they don't concede many either. It could be tight, possibly 1-0."

MANCHESTER UNITED (probable, 4-4-2): Barthez; P Neville, Brown, G Neville, Irwin; Beckham, Keane, Scholes, Giggs; Sheringham, Yorke.

PANATHINAIKOS (probable, 4-4-2): Nikopolidis; Henriksen, Goumas, Vokolos, Fyssas; Saric, Basinas, Karagounis, Kola; Warzycha, Liberopoulos.