Leinster and Ireland are facing a severe test of their reserves at loosehead prop with the news that Andrew Porter could be absent for up to a couple of months while Paddy McCarthy has suffered a “significant” foot injury.

Porter suffered a calf injury in training last Thursday while McCarthy was forced off in the 43rd minute of last Saturday’s dramatic 25-24 win over La Rochelle at the Aviva Stadium. Neither player is expected to be available for the opening stages of the Six Nations, which kicks off when France host Ireland on February 5th.

In the short-term, Jack Boyle (shoulder) could return for Saturday’s Investec Champions Cup clash with Bayonne at Stade Jean-Dauger (4.15pm local time/3.15pm Irish time, live on Premier Sports 2).

If that match comes too soon for Boyle, he should be fit in time for the Six Nations opener in Paris, with the Munster pair of Michael Milne and Jeremy Loughman also coming into consideration. It may also lead to Tom O’Toole converting back to loosehead.

Fullback is also stretched, albeit Hugo Keenan is nearing match fitness, as he is “increasing his on-field training” following his hip injury. Despite limping off gingerly with a foot injury last Saturday, Ciarán Frawley has not been ruled out of the Bayonne trip while Jimmy O’Brien is back in the mix, as is Garry Ringrose, RG Snyman and Tadhg Furlong.