Mikkola suffered an upper-body injury in Monday's 4-0 loss to Tampa Bay and is considered day-to-day, according to Jameson Olive of the Panthers' official site.
Mikkola went to the locker room late in the second period and ultimately did not return. Head coach Paul Maurice said that Mikkola attempted to return but was not able to. An update on Mikkola's status should surface before Saturday's home game against Montreal.