The Tottenham striker and the Manchester City defender are among five men who will join up with the rest of the 28-man squad in Dublin on their return because of club or personal commitments.

Champions League finalist John O'Shea, and Celtic duo Aiden McGeady and Darren O'Dea will also miss the trip to Portugal, while Cardiff midfielder Stephen MacPhail and Crystal Palace counterpart Sean Scannell will arrive after the FA Cup final and the Championship play-offs respectively.

There is a return to the squad for West Brom keeper Dean Kiely after a five-year absence, and places for the uncapped O'Dea, Scannell, Damien Delaney, Owen Garvan, Wes Hoolahan and Glenn Whelan.

Republic of Ireland squad for the friendlies against Serbia at Croke Park on Saturday, May 24, and Colombia at Craven Cottage on Thursday, May 29:

Goalkeepers: Colin Doyle (Birmingham), Dean Kiely (West Brom), Joe Murphy (Scunthorpe).

Defenders: Alex Bruce (Ipswich), Damien Delaney (QPR), Richard Dunne (Manchester City), Kevin Foley (Wolves), Stephen Kelly (Birmingham), Paul McShane (Sunderland), Darren O'Dea (Celtic), John O'Shea (Man Utd).

Midfielders: Damien Duff (Newcastle), Owen Garvan (Ipswich), Wes Hoolahan (Blackpool), Stephen Hunt (Reading), Aiden McGeady (Celtic), Stephen MacPhail (Cardiff), Liam Miller (Sunderland), Darren Potter (Wolves), Andy Reid (Sunderland), Martin Rowlands (QPR), Sean Scannell (Crystal Palace), Glenn Whelan (Stoke).

Strikers: Kevin Doyle (Reading), Robbie Keane (Tottenham), Andy Keogh (Wolves), Shane Long (Reading), Daryl Murphy (Sunderland).