Carlton defender Adam Saad will be sidelined for six weeks with the hamstring injury he suffered in their upset AFL loss to Adelaide.
While the hamstring injuries to Mitch McGovern and Adam Cerra are not as severe, Saad will be a big loss for the Blues given the rebound he gives them from half-back.
Carlton are entering a challenging run of games, starting with top side GWS on Saturday at Marvel Stadium.
The Blues then play Geelong, who are also unbeaten, followed by arch-rivals Collingwood, Melbourne and the tough away trip against Sydney.
Saad went off during last Saturday's match at Marvel Stadium, which the Crows won by two points.
It was Carlton's first loss of the season.
McGovern also was hobbled by a hamstring injury late against the Crows, and Cerra was a late withdrawal with the same problem after he was hurt at training.
But the Blues announced in their weekly injury update that McGovern and Cerra should be out of action for only one to two weeks.
They join a lengthy Carlton injury list that features 13 sidelined players.