He has been given 'a week off after not having a break since the start of the season'. The two scrum half spots are filled by Conor Murray and Boss' Leinster team-mate Eoin Reddan.
Ulster's Darren Cave and Robbie Diack - the only uncapped member of the squad - have made the cut after impressing in recent outings with the province.
Fit-again hooker Richardt Strauss is back in contention having made back-to-back appearances for Leinster, while Simon Zebo comes in to replace his Munster colleague Felix Jones (knee).
In all, 19 of the players included - seven backs and 12 forwards - saw action in the RaboDirect PRO12 over the weekend.
Centre Luke Marshall sustained a confirmed concussion playing for Ulster against the Dragons on Friday. The Ulster medical team will manage him through the return to play protocols this week.
The selected Ireland squad will train this week at Carton House. The team announcement press conference is scheduled for Thursday at 1pm.
IRELAND SQUAD (RBS 6 Nations v Italy):
Backs (14) -
Darren Cave (Belfast Harlequins/Ulster)
Gordon D'Arcy (Lansdowne/Leinster)
Robbie Henshaw (Buccaneers/Connacht)
Paddy Jackson (Dungannon/Ulster)
Dave Kearney (Lansdowne/Leinster)
Rob Kearney (UCD/Leinster)
Ian Madigan (Blackrock College/Leinster)
Fergus McFadden (Old Belvedere/Leinster)
Conor Murray (Garryowen/Munster)
Brian O'Driscoll (UCD/Leinster)
Eoin Reddan (Lansdowne/Leinster)
Jonathan Sexton (Racing Metro 92)
Andrew Trimble (Ballymena/Ulster)
Simon Zebo (Cork Constitution/Munster)
Forwards (19) -
Rory Best (Banbridge/Ulster)
Sean Cronin (St. Mary's College/Leinster)
Robbie Diack (Malone/Ulster) *
Cian Healy (Clontarf/Leinster)
Jamie Heaslip (Dublin University/Leinster)
Iain Henderson (Ballynahinch/Ulster)
Chris Henry (Malone/Ulster)
Dave Kilcoyne (UL Bohemians/Munster)
Mike McCarthy (Lansdowne/Leinster)
Jack McGrath (St. Mary's College/Leinster)
Martin Moore (Lansdowne/Leinster)
Jordi Murphy (Lansdowne/Leinster)
Paul O'Connell (Young Munster/Munster)
Peter O'Mahony (Cork Constitution/Munster)
Mike Ross (Clontarf/Leinster)
Rhys Ruddock (St. Mary's College/Leinster)
Donnacha Ryan (Shannon/Munster)
Richardt Strauss (Old Wesley/Leinster)
Devin Toner (Lansdowne/Leinster)
* Denotes uncapped player
Not considered for selection:
Tommy O'Donnell - received a stinger at the weekend and is facing a week's recovery
Tommy Bowe - tightened up after 30 minutes on Friday but finished the half as planned and will continue to follow a staged return to play programme
Isaac Boss - has been given a week off after not having a break since the start of the season
Felix Jones - took a knock to the knee and will be unavailable to train this week. He has been replaced in the squad by Simon Zebo