AC Milan will be expected to produce a win against Anderlecht in their Champions League group opener at the San Siro on Tuesday if they are to end their early season jitters.

The seven-time champions are tipped to win a Group C containing Spanish side Malaga, Zenit St Petersburg of Russia, as well as Belgian opponents Anderlecht.

But recent events at the San Siro suggest Massimiliano Allegri's side could face a battle to make it into the last 16 of this year's competition.

Milan, who finished league runners-up to Juventus last season, have conceded two home defeats either side of a 3-1 win away to Bologna in their first three league fixtures.

Allegri looked a frustrated man on the touchline on Saturday as his side fought frantically for a goal before succumbing 1-0 to supposedly inferior opposition in Bergamo-based side Atalanta.

He now wants a different Milan side to show better potential on Tuesday.

"We have to improve and forget the results we've had. Tuesday for us is a chance to pick up the pieces and move on," said the 45-year-old, who since taking over in 2010 has led Milan to the league title and Super Cup title in 2011.

Looking at the big picture, that is easier said than done.

Milan sold Zlatan Ibrahimovic and Thiago Silva to Paris St Germain in the summer and the departure of long-serving stars like Alessandro Nesta, Filippo Inzaghi and Clarence Seedorf has left Milan almost unrecognisable.

Although set to welcome back midfielder Riccardo Montolivo after a recent knock, the Rossoneri are still awaiting the return from injury of Brazilians Pato and Robinho.

And while Dutchman Nigel De Jong, Ghanaian Kevin Prince Boateng and Spaniard Bojan Krkic are exciting prospects, Allegri's struggle to forge a convincing football-playing team is coming under increasing scrutiny.

Milan dominated Atalanta throughout Saturday's fixture but paid for a series of misses when a 65th-minute strike by Luca Cigarini gave the visitors a shock 1-0 win.

Team skipper Massimo Ambrosini, 35, is set to start on Tuesday despite having to come off midway through the second half with a foot injury.

But the long-serving midfielder, who has regularly risen to the occasion in key Champions League fixtures for his club, says it's time to forget the past.

"We need time to accept that this team has changed... but the fact they (players) have left should not be an excuse," said Ambrosini.

"Last season we had a lot of quality players that we could rely on. Now, we have to start doing things that perhaps last year we didn't have to."

On paper Milan look the stronger team but having twice won the title (1994, 2007) after meeting Anderlecht earlier in those respective campaigns, the Rossoneri fans have good reason to have less faith this time around.