Tannadice boss Craig Levein was delighted to finally get his man at last and O'Donovan, who will line up against Celtic in the Clydesdale Bank Premier League on Sunday, revealed his confidence has already taken a massive boost by simply working with a manager who he knows rates him highly.
"There was interest from clubs in England as well but I knew that Craig Levein had tried to get me for a long time, so that's why I chose United.
"It's a great opportunity for me to come up here and play some games in a competitive league.
"It's a high standard and the chance to play against the Old Firm is something I'm looking forward to. Celtic are the biggest name back home and I can't wait for Sunday. They're a good side but we can beat them, there's no doubt about that.
"It's a big test of our ability but, from what I've seen so far, we've definitely got the players.
"We've put pressure on ourselves after Monday's defeat to Hamilton but we've got enough in our locker to cope."