Doncaster have signed the former Arsenal defender following a trial period, although the club has not yet officially confirmed his arrival.
Olowu has been pictured holding a Rovers shirt and posing for photographs, suggesting that the deal is done. It is claimed that he has signed a short-term contract at the Keepmoat Stadium until January.
After being released by Arsenal at the end of last season, the 21-year-old joined United on trial at the start of August.
He featured in pre-season matches for the Under-23s against both Kidderminster Harriers and Sheffield Wednesday, plus Premier League 2 fixtures against both Chelsea and Manchester City, but was not offered terms by United for him to stay at the club and put down roots.