"I met the new manager, Ricky Sbragia," O'Donovan told the Irish Sun. "He didn't make me any promises but he told me to get in and get training and we'll see what happens.
"We got on well before and I'm looking forward to having a good relationship with him."
O'Donovan said that returning to the North East felt like going back to school after the summer holidays.
"It was like the first day at school," he insisted. "There was a lot of new players, new faces and a different agenda but I'm delighted to be back at Sunderland.
"I haven't spoken to Roy Keane but I wish him all the best. He signed me and he played me, he's a fellow Corkman and I enjoyed working for him. Hopefully he will go on to bigger and better things in the future."
As for his own future, the 23-year-old is reluctant to predict what the future has in store.
"I'm not looking too far into the future, it's 'take it day by day' for now and get used to training here and adjusting to the Premier League."