The giant defender nicknamed ‘The Giraffe’ turned down a new contract at Carlisle after joining The Cumbrians in August 2010.
Michalik is expected to be on the bench for Pompey’s League One match with Walsall today.
He has penned a one-month deal with Michael Appleton’s side as per the rest of the squad. His arrival comes following the expiry of Paul Connolly’s loan spell. Portsmouth are restricted to a squad of 20 players so it is a case of one in, one out for any transfer movement and their one month contracts is allowing them to do this.