Celtic have completed the signing of Mark Wilson from Dundee United for £500,000.

The 21-year-old has signed a four-and-a-half year contract with the Parkhead outfit and could make his debut in the game at Motherwell at the weekend.

Gordon Strachan has swooped for the defender in a bid to increase his options at the back and maintain a commanding lead at the top of the SPL table.

Dundee United chairman Eddie Thompson is sad to see Wilson leave Tannadice.

"We didn't want to lose him but he had a clause in his contract stating that, if a club met the agreed asking price, he could go," said Thompson.

"We were faced with the possibility of him leaving on a pre-contract last season so at least this way the club has got something back."