AC Milan can secure qualification for the Champions League knock-out rounds if they come away from Belarus with three points on Tuesday.
Milan and Barcelona have been totally dominant in the group stages so far and if they both win they will both be through to the last 16 with a winner takes top spot clash to come at the San Siro in three weeks' time.
If the Italians beat BATE Borisov then they will have qualified unless Viktoria Plzen stun the Spanish title holders and win in the Czech Republic.
Milan already beat the Belarussians 2-0 at the San Siro two weeks ago and won by the same score on their only previous visit to their opponents in September 2001.
That match was played in Minsk's Dinamo Stadion, as this one will be, as the Haradzki Stadium in Borisov doesn't meet European standards.
Milan come into the game in fine form in the league following four straight wins, and five in all competitions, but they have a couple of worries before heading to Minsk.
Striker Antonio Cassano was taken ill on Saturday night when returning from Milan's 3-2 victory at Roma and had to be admitted to hospital.
He was allegedly having difficulty speaking and moving and had to spend a second night at the hospital after being transferred to the neurological department.
Milan club doctor Rodolfo Tavana ruled Cassano out of the trip to Belarus as he had to undergo tests on his heart and brain.
"The boy is not well and we're looking into it," said Tavana. "He won't be travelling to Minsk and will be out of action for several days."
Milan are already without Brazilian striker Pato and Italian full-back Luca Antonini while Ghana midfielder Kevin-Prince Boateng is a doubt after picking up a knock against Roma and was due to be assessed on Monday morning.
At least veteran Dutch midfielder Clarence Seedorf is expected to be back from a knee problem for the trip.
If there is hope for Borisov it will be that Milan have been far from secure at the back this season.
They have let in 14 goals, giving them the fifth worst defence in Serie A.
Last week chief executive Adriano Galliani felt compelled to ring Allegri and remind him that the best defence rather than the best attack usually wins the league but Milan still conceded two at the weekend.
Surprisingly, Allegri pointed at veteran Alessandro Nesta and told his stallwart to improve following the Roma game.
"We conceded a goal from a corner and we have to improve there," he said.
"On the second Nesta needed to be a little more decisive and maybe just hoof the ball into touch.
"But the important thing was to win and earn our fourth successive win in the league."
"Now we have the Champions League and then we'll prepare for Catania, who are doing very well at the moment."
"The important thing was to win but then you always have to look to maintain balance and look to see where you can improve."
"But the technical mistakes apart, we defended all together and that has improved."
BATE have already wrapped up their sixth straight league title - the Belarus season runs in calendar years - but already look to be in a battle with Plzen for third place and a spot in the Europa League in the new year.