Inter Milan midfielder Dejan Stankovic (pictured) twisted his left knee in training and is struggling to be fit for Saturday's home game with Cagliari.
The leaders, who have a six-point advantage as the championship resumes from a three-week break, may bring in Luis Figo or Luis Jimenez to replace the Serbian.
Influential right back Maicon is suspended while troubled striker Adriano, continually linked with a move in the media, is back in training after a groin problem.
David Beckham is expected to be on the bench for his first Serie A game when third-placed AC Milan visit midtable AS Roma on Sunday.
Marco Borriello, Gennaro Gattuso, Alessandro Nesta and Daniele Bonera are all still out for the Rossoneri.
Roma captain Francesco Totti misses the visit of Milan with a thigh injury which could keep him out for another month.
Serie A joint-top scorer Diego Milito is out of Genoa's home game with Torino on Saturday because of a groin strain with media reports saying the Argentinian could miss two more games.
The match will go ahead despite heavy snow delaying the relaying of the worn surface at the Marassi.
Fit-again goalkeeper Gianluigi Buffon, back after being injured for three months, is unlikely to be risked when second-placed Juventus host Siena on Sunday.
Alex Manninger is poised to continue between the posts while Juve's website said striker Vincenzo Iaquinta was winning his battle to shake off a muscle pull.
Siena are without suspended goalkeeper Gianluca Curci.
