The Ivory Coast management informed City on Thursday that Toure was required to attend a team meeting in Paris on Saturday ahead of a flight to Abu Dhabi for a two-week training camp before the African Nations Cup.
Blues officials confirmed the information, which appeared to rule Toure out of this weekend's encounter, when Mancini has claimed he might not have enough players to fill his substitutes' bench at the Etihad Stadium.
However, Ferguson is not so sure.
The United boss' knowledge of the tournament does not appear that extensive - his claim that Toure could be back inside 10 days is wide of the mark given the Ivory Coast's first game is not until January 22 - but in the art of managerial mind games, he is a master.
"I am not sure Toure won't be available for Sunday," he said. "He probably will.
"I don't know the whole background but apparently, he doesn't need to meet up until Monday I read somewhere, which suggests he should be playing on Sunday."
Toure himself has spoken of his disappointment at missing the game, which suggests the case is now closed.
Even if the former Barcelona man is missing though, Ferguson is not convinced it can be as detrimental to City's chances of landing some silverware this season as Mancini seems to feel.
"All the teams who have African players have never really suffered much," he said.
"If you check the records, they all seem to sail through it.
"I don't think it makes a great impact when you have a squad of players.
"There are plenty to occupy those positions until they come back."