The Citizens welcome the Italian side, who include former England left-back Ashley Cole in their squad, to the Etihad on Tuesday evening for the second round of group matches in Europe’s premier competition.
The England goalkeeper was omitted for the weekend’s 4-2 victory at Hull City in the Premier League - Willy Caballero retaining the gloves following a midweek appearance in the League Cup.
But City boss Pellegrini was quick to explain it was a straightforward case of squad rotation as he said 45-times capped shot-stopper would be back on duty against Roma.
Joe Hart (right) was on the City bench, along with Frank Lampard on Saturday
Asked the question whether Hart would return directly, the Chilean said: “Yes, yes. He is in a very good moment.
“It's a crucial game because Roma won their first match and we lost.
“It will be a very tough group and we cannot drop points here at home. It's very important for us to win that game.”
Caballero has kept a clean sheet against Sheffield Wednesday last week and could do little to prevent Hull’s two goals on Saturday - an unstoppable own-goal from Eliaquim Mangala followed by an Abel Hernandez penalty.
And City captain Vincent Kompany believes that his side are fortunate to have two keepers of such pedigree.
“We're lucky to have two top-class goalkeepers and there is not much in it," he said.
“I have gained so much playing with Joe and I am gaining a lot playing with Willy. At this level there can't ever be much between the goalkeepers because it's a long season and you need everyone.”
