The 22-year-old Italian fell ill at half-time in Saturday's 2-2 draw with Cardiff and was taken to hospital on a drip.
But Borini was released by medical staff last night after his condition improved.
Manager Gus Poyet revealed Borini had been suffering from a virus in the run-up to the game and would not join his team-mates on their flight back to the north east.
Speaking after the game, he said: "We were really, really worried as he was really, really sick so the doctor decided rightly to take him to hospital but he has been released now. It was a virus or sickness, so no problems."
A club spokesman said on Sunday: "Fabio is feeling much better and will return to Wearside today."
Borini had played in the first half for Sunderland, who fought back from 2-0 down to claim a draw at the Cardiff City Stadium.