Michalek sustained the injury in the third period of a 4-1 win over New Jersey on Saturday when he dived to block a slap shot by New Jersey's Rod Pelley.
Coach Dan Bylsma says Michalek will not need surgery. The injury forces the team to shuffle its defensive pairings. Paul Martin, who had been teaming with Michalek, will now work with Kris Letang.
Bylsma also said center Evgeni Malkin, limited by soreness in his surgically repaired right knee, will make the trip with the team on Tuesday to play the New York Islanders. Malkin hasn't played since an overtime loss to Washington nearly two weeks ago.