The Swedish frontman has been linked with a move to Stoke City in recent weeks, having previously worked under Britannia Stadium boss Mark Hughes during the Welshman's spell in charge of City.
And Pellegrini revealed on Tuesday that Guidetti would be making a temporary move away from the Etihad Stadium, but was unsure whether a switch to Stoke is a done deal.
"Yes, John (Guidetti) is going on loan," he said. "I don't know if he has already arranged with Stoke, but he is going on loan.
Guidetti has made just one League Cup appearance since signing for City in 2008, and previously spent time on loan at former club IF Brommapojkarna, Burnley and Feyenoord.
Hughes is hopeful of pushing through a deal, telling the Sentinel earlier this week: "If we can get him in, he's a player that can add to what we have got and we are trying to add different options to our attack.
"He's a natural goalscorer and if we can get him into the right areas, he will take chances."
