The players were all members of 35-man two-day training camp that ended in Dublin, but coach Eddie O'Sullivan was unable to name Leinster wing Horgan because of the knock he picked up in the opener against Scotland.
His absence has paved the way for the return of London Irish wing Justin Bishop after a hand injury, but there is still a vacancy in the forwards for a second row.
O'Sullivan will announce his starting line-up and replacements for the Millennium Stadium on Tuesday.
Ireland squad to face Wales in the RBS 6 Nations game in Cardiff on March 22:
Backs: J Bishop (London Irish), G Dempsey (Leinster/Terenure College), G Easterby (Llanelli), R Henderson (Munster/Young Munster), D Hickie (Leinster/St Mary's College), D Humphreys (Ulster/Dungannon), J Kelly (Munster/Cork Constitution), K Maggs (Bath), G Murphy (Leicester), R O'Gara (Munster/Cork Constitution), B O'Driscoll (Leinster/Blackrock College, capt), P Stringer (Munster/Shannon).
Forwards: S Byrne (Leinster/Blackrock College), V Costello, (Leinster/St Mary's College), L Cullen (Leinster/Blackrock College), J Fitzpatrick (Ulster/Dungannon), A Foley (Munster/Shannon), K Gleeson (Leinster/St Mary's College), J Hayes (Munster/Shannon), M Horan (Munster/Shannon), G Longwell (Ulster/Ballymena), M O'Kelly (Leinster/St Mary's College), A Quinlan (Munster/Shannon), F Sheahan (Munster/Cork Constitution).