Lee Wilkie had been on trial at Tannadice

Wilkie has been training at Tannadice for the last eight weeks since agreeing a severance package with Dundee and has penned a pay-as-you-play contract.

"Other teams were interested, but I wanted to stay in Dundee," said Wilkie.

"It is a good move for me and the main thing at the moment is getting match-fit but this is the best shape I have been in and I feel strong."

Wilkie had played three reserve games in a bid to prove his fitness after serious knee problems threatened his career.

"I will not be ready to play against Celtic on Saturday and need a few more reserve games before I can think of the first team," added the centre-half, who has suffered from three cruciate ligament injuries.

United player-manager Brewster had said: "He has impressed me during his trial and there are not many teams who don't want a fully-fit Lee Wilkie, because he is a top-class defender and has come on leaps and bounds here."

Wilkie had already made two ill-fated comeback attempts while with neighbours Dundee.

He negotiated his release after refusing a pay cut along with several other high earners at Dens Park.

The 26-year-old has been training with United while attracting interest from the likes of Plymouth Argyle and Raith Rovers.

"He's in good shape physically and the three games he has played have allowed him to covercome the mental barrier," added Brewster.

"That's sometimes the most important and lengthy part to rehabilitation.