Pato and Nesta to return for Milan
Brazilian Pato has not played this year after a thigh injury and coach Leonardo has frequently given his place on the right of his front three to David Beckham.
Centre-back Nesta has been out since suffering a leg muscle strain against Siena last month and third-placed Milan have not won a league match since.
Full-back Massimo Oddo is also in Milan's squad for Friday's home game after a long layoff, the club said on their website.
Leonardo still has injury worries ahead of Tuesday's Champions League last 16 first leg tie against Manchester United.
Fitness problems meant he was unable to call on defenders Gianluca Zambrotta and Luca Antonini, midfielder Clarence Seedorf and forward Marco Borriello for the Udinese game.