Two league draws in a row for the Serie A leaders were followed by Saturday's 4-0 romp against Parma, with cut-price January recruits Antonio Cassano and Mark van Bommel playing a part in the victory.
The pair, along with former Ajax Amsterdam player Urby Emanuelson, are ineligible to play for the seven-times winners in the Champions League having featured in earlier rounds with Sampdoria and Bayern Munich.
Milan knew this when they signed them but the pursuit of their first scudetto since 2004 takes precedence over European competition this season.
"We're first in the championship for the first time in years so it's logical to think Milan's objective is the league title," Allegri told reporters.
NO JOKER
Cassano's absence means Allegri is forced to play Zlatan Ibrahimovic, Robinho and Alexandre Pato as his front three, with no 'joker' on the bench to allow the coach to shuffle the pack if goals are not forthcoming.
Midfielders Andrea Pirlo and Massimo Ambrosini miss out due to injury and the combative Van Bommel could at least have patrolled the area in front of the back four even if pinging 60-metre Pirlo-esque passes is not his strong point.
Spurs, preparing for the biggest game in their first Champions League campaign, have problems too with left winger Gareth Bale missing because of a back injury and two more creative influences doubtful.
Bale lit up the San Siro with a hat-trick in the 4-3 defeat at holders Inter Milan in the group stage and was relishing a return although with AC Milan among the clubs casting an eye, his absence may be a blessing in disguise if Spurs want to keep him.
Rafael van der Vaart and Luka Modric are also key pieces in manager Harry Redknapp's jigsaw but missed the 2-1 win at Sunderland in the Premier League on Saturday.
"They're struggling at the moment. Luka's had his appendix operation and has just started jogging. Rafa's got a calf strain," said Redknapp who has Jermaine Jenas suspended.
"Hopefully they won't be too long. It's difficult to know."
Probable teams:
AC Milan: 32-Christian Abbiati; 17-Massimo Oddo, 33-Thiago Silva, 13-Alessandro Nesta, 77-Luca Antonini; 8-Gennaro Gattuso, 16-Mathieu Flamini, 10-Clarence Seedorf; 70-Robinho; 11-Zlatan Ibrahimovic, 7-Alexandre Pato
Tottenham Hotspur: 1-Heurelho Gomes; 22-Vedran Corluka, 20-Michael Dawson, 13-William Gallas, 32-Benoit Assou-Ekotto; 7-Aaron Lennon, 12-Wilson Palacios, 40-Steven Pienaar, 21-Niko Kranjcar; 15-Peter Crouch, 18-Jermain Defoe
Referee: Stephane Lannoy (France)
