The Swede has been sensational on-loan at Feyenoord this season.
McClaren told the Daily Mail: "When I was at Forest at the beginning of the season, I spoke to City to try to get Guidetti on loan. He's that sort of old-fashioned English striker that works so hard, is a good target and has the knack of scoring. That's what I saw, that's what I liked. He's a handful, the centre half never gets a rest.
"Now he needs to go on a bit, play back in England. He has the ability. For Sweden he'll be an impact player, and a bloody good one. A nice one to have in your squad."