The former Everton defender was a regular in City's Premier League-winning side last season but has been in and out of the starting XI this campaign.
He was dropped for their Champions League defeat to Real Madrid last month and was named on the bench again for the weekend victory over Fulham, with summer signing Matija Nastasic preferred as Vincent Kompany's centre-back partner.
However, Mancini has stressed that this is not down to a lack of faith in Lescott, but rather a case of competition for places and the need to rotate his squad.
"He is one of the best defenders. But I have six or seven defenders and I made a different choice last week and in Madrid," he said.
"On Wednesday I will decide again, but Joleon is an important player for us."
Lescott joined City from the Toffees in 2009 for a reported £22m fee.