Leonardo Bonucci is a doubt for Juventus' trip to Chievo this weekend after suffering the recurrence of a thigh injury, the Serie A leaders have confirmed.
Bonucci limped out of Juve's 1-1 draw with Lyon in the Champions League on Wednesday and underwent tests to ascertain the extent of his injury.
As Allegri's side prepare to visit Stadio Marc'Antonio Bentegodi - a stadium where they have won seven of their last eight matches - on Sunday, Bonucci's fitness has become a major concern.
"Having been substituted in the second half of Wednesday's draw with Les Gones [Lyon], Leonardo Bonucci underwent tests which revealed a recurrence of an injury previously sustained to his left thigh," a club statement read.
"The defender's condition will be monitored closely again tomorrow."