The striker was surprisingly left out of the Serie A club's squad for the Champions League showdown at Chelsea amid reports of a renewed feud with his boss.
Inter president Massimo Moratti is desperate to hang on to both Mourinho and a player seen as one of the country's most exciting prospects, but attempts to mediate between the pair have been difficult.
Super Mario: Inter striker Balotelli is highly rated at San Siro
Arsenal and Manchester City are both reported to have expressed an interest in Balotelli, while Chelsea boss Carlo Ancelotti is also a confirmed admirer of the 19-year-old.
Balotelli missed Inter's weekend defeat by Catania because of a niggling injury, but his omission was seen as precautionary and defender Marco Materazzi has confirmed he was fit to travel to England.
Mourinho refused to answer questions about Balotelli at his Stamford Bridge press conference on Monday evening, but Materazzi said: 'Mario was not in the squad against Catania because he had a problem with his knee, but today it's a technical choice.'
The boss has often criticised the over-confident Balotelli this seasonand placed him down the pecking order behind Samuel Eto'o, Diego Militoand January recruit Goran Pandev.
Frozen out: Balotelli (centre) trains with Inter on Monday, but later missed the plane to London
The 6ft 3in star they call 'Super Mario' does not help his popularity by openly supporting AC Milan and he was at the San Siro the Rossoneri's Champions League first leg defeat by Manchester United last month.
His agent Mino Raiola was spotted leaving AC Milan's headquarters on Monday, but he denied his presence there had anything to do with Balotelli, and Inter would almost certainly seek to sell him abroad if a summer exit is unavoidable.
Mourinho's departure, however, would change the landscape. The Portuguese is the favourite to succeed Manuel Pellegrini if there are any more slip ups at Real Madrid, while Mourinho has also spoken of a desire to return to England when the time is right.
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