The Manchester City striker, who joined Madrid on loan for the second half of last season, watched from the stands as Real beat Leicester City 2-1 in a pre-season friendly at the King Power Stadium.
Asked whether the club were looking to sign the former Togo international on a permanent deal, Mourinho replied: "No. He is here because he is our friend and he belongs to us. He is one of us.
"He was with us for six months and went to the heart of everybody. He is a great lad and everybody loves him.
"If he comes he comes, if he doesn't it doesn't matter. We will all know by August 31 who is in and who is out and where they are playing," he added.
The 27-year-old's future at City is in doubt after the club recently signed Sergio Aguero from Athletico Madrid, but the former Arsenal man has been linked to a number of other teams, including Tottenham Hotspur.