Ian Madigan is primed for his first RBS 6 Nations appearance of the season in Saturday's title-decider against France in Paris.
The Leinster fly-half will provide cover from the bench for Johnny Sexton, on the occasion of Brian O'Driscoll's 141st and final Test appearance.
Fit-again Peter O'Mahony is the sole change to the starting line-up from the 46-7 hammering of Italy in Dublin last weekend.
Iain Henderson drops to the bench, to cover lock and back row, with Jordi Murphy retaining a replacements role and Rhys Ruddock dropping out of the squad.
Ulster's Paddy Jackson has deputised for Racing Metro fly-half Sexton throughout the Six Nations so far, but misses out for the Stade de France showdown.
Madigan could find himself thrust into Ireland's highest-pressure Six Nations situation since their 2009 Grand Slam decider against Wales in Cardiff, if he joins the fray in the closing stages.
The 24-year-old has only 11 Leinster starts to his name this term too, sharing duties with Kiwi playmaker Jimmy Gopperth.
Now head coach Joe Schmidt has backed the Leinster out-half to shoulder a hefty burden, as Ireland chase just their third win in 42 years in Paris.
Schmidt will back seven-cap Madigan's extra versatility on the bench, able to cover inside centre as well as fly-half.
Munster captain O'Mahony returns after the hamstring problem that kept him out of the seven-try Italy drubbing.
Conor Murray and Cian Healy have both overcome niggling problems to retain their starting berths.
Scrum-half Murray's illness forced him out of the Azzurri rout in the first quarter, but Munster's British Lion had made a full recovery.
Wrecking ball loosehead prop Healy trudged out of the final stages in Dublin last weekend after picking up an ankle strain.
The 26-year-old Leinster front-rower spent Saturday night with his foot in a compression boot, and the precautionary measure paid dividends with Healy back to full training as early as Tuesday.
O'Driscoll will extend his Six Nations appearance record to 65 in his final international before his summer retirement.
The 35-year-old Leinster stalwart and Gordon D'Arcy will extend their world-record international centre partnership to 56 joint appearances.
Lancaster announced there could be a late change to the line-up as the partner of loosehead prop Joe Marler is due to give birth to their first child.
If Marler is unable to make it to Rome in time for the captain's run on Friday afternoon, Mako Vunipola will be promoted to the starting XV with Mullan taking his position on the bench.
"Joe's partner is in labour as we speak so we're waiting to see how that goes. We'll make a decision on Friday," Lancaster said.
"He's got to be at the captain's run. I spoke to Joe this morning and the good thing is we have a British and Irish Lion on the bench in Mako, who wants to start.
"Matt played in the autumn internationals and is a good player to come in on the bench."
Lancaster is pleased that Tuilagi is available to face Italy at the Stadio Olimpico.
"Manu has had that extra week's training he needed, so he's ready. He's a good player," he said.
England prevailed 19-15 in Rome two years ago and 18-11 in the return fixture at Twickenham last season - two narrow wins that have made Lancaster cautious over targeting anything other than victory.
"Winning is the priority. We went to Rome two years ago and it was very difficult," he said.
"Italy beat France in the Six Nations last year and Ireland struggled.
"Even Australia struggled in 2012. It's not an easy place to go and get points, and we know what's coming.
"This is a fantastic opportunity to finish the Six Nations on a high. We want to back up our recent good performances.
"The character we've shown throughout has been outstanding. The attitude has been the best I've known."
Ireland team to face France
By Nick Purewal
Ireland team to play France in the RBS 6 Nations at the Stade de France on Saturday:
IRELAND: R Kearney (Leinster), A Trimble (Ulster), B O'Driscoll, G D'Arcy, D Kearney (all Leinster), J Sexton (Racing Metro), C Murray (Munster), C Healy (Leinster), R Best (Ulster), M Ross, D Toner (both Leinster), P O'Connell (capt), P O'Mahony (both Munster), C Henry (Ulster), J Heaslip (Leinster).
Replacements: S Cronin, J McGrath, M Moore (all Leinster), I Henderson (Ulster), J Murphy, E Reddan, I Madigan, F McFadden (all Leinster).