Nesta to miss Sparta clash
The Italian international limped out of Il Rossoneri's 3-2 derby win over Internazionale on Saturday with a muscular problem in his leg.
Nesta is not likely to recover in time for the second round, first leg clash in Czech Republic, with Milan boss Carlo Ancelotti likely to turn to veteran Paolo Maldini to anchor the European Cup holders' backline.
Maldini, who missed the thrilling encounter against Inter through suspension, looks set to join striker Filippo Inzaghi and midfielder Massimo Ambrosini in returning to Ancelotti's squad for the clash against Sparta.
Nesta will also be joined by Danish striker Jon Dahl Tomasson, who looks set to miss the first leg encounter through injury as well.
Milan will want to get a positive result from their trip to Eastern Europe on Tuesday before returning to San Siro for the second leg.