Horan has been out of action since playing against Treviso in the Heineken Cup on October 17 when he left the field complaining of dizziness.

Tests showed he had an irregular heartbeat but has now been passed fit to play in Shannon’s Munster Senior Cup semi-final against UCC on Saturday.

That should pave the way for Horan to return to Munster propping duty with boss Tony McGahan desperate for the return of one of his most experienced players ahead of a busy schedule.

It was originally though Horan would be out until the start of February but he now faces a fight on his hand to wrest the No.1 shirt off Leinster’s Cian Healey in time for the Six Nations opener against Italy on February 6.

After taking part in a full training session for Munster last week, team manager Shaun Payne welcomed Horan’s return as a late Christmas present.

He said: “Marcus continues to progress very well. Towards the end of this week, we might look to get him some game time if he is ok to play.

“That would obviously put him in the frame for the Scarlets, and obviously moving forward towards the play-off rounds of the ERC.”