Powerhouse Lions Test player Horgan replaces Andrew Trimble, who must now wait and see how Peter Stringer and Brian O'Driscoll cope with their injury worries before knowing whether he will be in the team.

O'Sullivan has left two places vacant in the starting XV and named a squad of 25, with the vacancies at outside centre and at scrum-half as he waits on the fitness of the two injured men.

This means that Eoin Reddan, as well as Trimble, remain in contention for a place in the squad.

If both O'Driscoll and Stringer come through this week and can take their place in the team, then Isaac Boss and Geordan Murphy will remain on the replacements.

If Stringer does not prove his fitness, New Zealander Isaac Boss will start the game, with Eoin Reddan coming onto the bench.

If O'Driscoll is ruled out, Geordan Murphy will come onto the wing, with Shane Horgan moving to centre to partner Gordon D'Arcy, and Trimble on the bench.

Jamie Heaslip has also been named as a possible replacement as a precaution for Denis Leamy.

The team will be led by second row Paul O'Connell if Brian O'Driscoll does not play.

Ireland: 15 Girvan Dempsey, 14 Shane Horgan, 13 AN Other, 12 Gordon D'Arcy, 11 Denis Hickie, 10 Ronan O'Gara, 9 AN Other, 8 Denis Leamy, 7 David Wallace, 6 Simon Easterby, 5 Paul O'Connell, 4 Donncha O'Callaghan, 3 John Hayes, 2 Rory Best Belfast, 1 Marcus Horan.
Replacements: 16 Jerry Flannery, 17 Simon Best, 18 Mick O'Driscoll, 19 Neil Best or Jamie Heaslip, 20 Isaac Boss or Eoin Reddan, 21 Paddy Wallace, 22 Geordan Murphy or Andrew Trimble.

Date: Sunday, February 11
Kick-off: 15:00 GMT
Venue: Croke Park, Dublin
Referee: Steve Walsh (New Zealand)
Touch judges: Kelvin Deaker (New Zealand), Malcolm Changleng (Scotland)
Television match official: Peter Allan (Scotland)
Assessor: Steve Hilditch (Ireland)