Troncon in as Italy opt for experience
Troncon, Italy's most capped player with 85 appearances, missed the whole of last year's Six Nations tournament because of a knee injury.
But Italy coach John Kirwan has opted for the experienced 31-year-old because Griffen is struggling with a hamstring problem.
Griffen, who has been Italy's first-choice number nine in recent times, is likely to start on the bench where he will be joined by New Zealand-born winger Kaine Robertson, who played against Italy for the World XV in last Saturday's All Star match in Catania.
Captain Marco Bortolami has recovered from flu and will lead his side while Luciano Orquera, born in Argentina, will make his debut on the wing.
Kirwan's only real concern is at hooker, where he will decide between Fabio Ongaro and Giorgio Intoppa closer to the match.
Neither player is 100% with Ongaro sustaining a groin injury in training earlier this week while Intoppa, like Bortolami, has also been struggling with flu.
Both forwards are expected to be fit, however, and Kirwan is likely to go for Ongaro to start.
In the meantime, Italy's defensive co-ordinator Grant Doorey is looking forward to seeing his two centres clash with exciting Irish pair Brian O'Driscoll and Gordon D'Arcy on Sunday.
O'Driscoll and D'Arcy are rated as the leading centre partnership in the world but Doorey insists opposite numbers Gonzalo Canale and Andrea Masi will be ready for them in Rome.
Doorey, a former Australia team manager and rugby league player, has been impressed by Canale and Masi and believes they can form a formidable partnership.
Doorey said: "D'Arcy was the best Irish player in the last RBS 6 Nations, he is a great attacker and a very dangerous defender.
"As for Brian O'Driscoll, there is nothing to say anymore, for years he has been perhaps the most respected centre in international rugby.
"He is a warrior in defence and very dangerous with ball in hand you never know what he can do."
"They really make a great partnership, but we also have two players with enormous quality in Gonzalo Canale and Andrea Masi.
"Both players are wonderful in a tackle situation, they are two great players who are waiting with great patience for this RBS 6 Nations.
"This could be a battle between two great pairs couples and Sunday's match promises fireworks from those players," he said.
Doorey belies Italy can witstand the Irish threat in attack. "Our defensive line worked hard and well this week and now we are ready to face the Irish," he said.





