Troncon, a 34-year-old at his fourth World Cup, was included in the side announced by coach Pierre Berbizier at the squad's St-Remy-en-Provence base in the south of France.

He started Italy's first pool match, a 76-14 rout by New Zealand in Marseille, and came on as a replacement in the 24-18 win over Romania to take his caps tally to 99.

Troncon, one of eight changes from the starting line-up against Romania, one of them positional, is partnered at halfback by Roland De Marigny.

"There are some injured players and we made our decision with that in mind," Berbizier told reporters.

"Alessandro Zanni is injured, so is Josh Sole, that's why Sergio Parisse will have to play as number six and not as number eight like he always does.

"He's done that for us before. It's not ideal, but we have to adapt to the situation."

In the positional change, Andrea Masi moves from left wing to centre.

Matteo Pratichetti comes in on that wing while Pablo Canavosio returns from injury on the right.

Italy are expected to beat Portugal with ease as they prepare for a pool showdown with Scotland in St Etienne on September 29.

In their last meeting, a World Cup qualifier last October, Italy demolished Portugal 83-0. AAP