The centre-back has not featured for the Premier League champions since 26th January, after suffering a calf injury, with City slipping to 15 points behind leaders Manchester United in his absence.
The news of his return to international action could lead to a club versus country row with Mancini, who anticipated Kompany sitting out the international fixtures in order to recover fully.
Ahead of last weekend's game with Everton the City boss said: "We don't want to take a risk at this moment because we have one game and then it is the international break so it's best he is recovering.
"The calf is a dangerous injury. If you don't recover very well then you can have a problem for four, five or six weeks in a row."
But Belgium coach Marc Wilmots said Kompany had trained for three consecutive days, with no injury problems, and is set to play on Tuesday.
"I can't say what is going to happen tomorrow, but I expect him to be 100 per cent fit," he said.
"If he is able to train well on Monday, he will start on Tuesday. I first want to see that he is 100 per cent. He is the captain and he's ready."