The strong Ireland lock will be rested for Saturday’s Magners League clash with Irish rivals Connacht, but McGahan has otherwise named a full-strength squad.
The league leaders are chasing a double this year after advancing to the Heineken Cup semi-finals following Sunday’s win over The Ospreys and, O’Callaghan apart, all the stars from that clash in Thomond Park could feature again.
Donncha Ryan, Michael Essex and Nick Williams, meanwhile, are added to the group for the visit of the league's bottom team.
Munster squad v Connacht:
Denis Hurley, Paul Warwick; Doug Howlett, Keith Earls, Lifeimi Mafi, Barry Murphy, Ian Dowling; Ronan O’Gara, Peter Stringer, Tomás O’Leary; Tony Buckley, Marcus Horan, John Hayes, Michael Essex, Jerry Flannery, Denis Fogarty, Mick O’Driscoll, Paul O’Connell, Donncha Ryan, Alan Quinlan, David Wallace, Niall Ronan, Denis Leamy, Nick Williams.