O Callaghan is unavailable because of a strained medial ligament in his right knee, but following a scan he hopes to be fit in time for consideration against Italy at Lansdowne Road on March 20.

The squad of 22 from which the Ireland team to play England will be picked, will be announced on Friday next.

The following players have been invited to join the squad chosen against Wales for a mini Camp in Dublin on Tuesday to Thursday of this week:

Gavin Duffy (Harlequins), Rob Henderson (Munster), Anthony Horgan (Munster), John Kelly (Munster), Bernard Jackman (Connacht), Gary Longwell (Ulster), Matt McCullough (Ulster), Neil McMillan (Ulster).