Togo strike star Adebayor, 26, yesterday completed a loan move to Spanish giants Real Madrid.
And Zabaleta told The Sun: "I think the situation was becoming difficult as in the last few games he wasn't even in the squad as City signed Edin Dzeko. Mancini was counting on Dzeko as a striker.
"In a way the situation of Adebayor was a bit strange, coming to training every day but then not being in the squad. For a player of his quality it was difficult."
Adebayor, who joined from Arsenal in a £25million switch just 18 months ago, proved a massive flop having scored just one league goal this season.
Zabaleta added: "He didn't have a lot of time on the pitch. The way Mancini plays, Carlos Tevez is the only striker in the team but that is working well."