The Blades can today announce that four young players have put pen to paper on extended contracts.

David McAllister, Erik Tonne, Jordan Chapell and Jack Adams have all signed deals which commit their immediate future to United.

Irishman McAllister and Norwegian Tonne have both been on the fringe of the first team this season and have scored senior goals. Chapell, 20, came on as a late substitute in the FA Cup victory over Salisbury City, whilst promising striker Adams, 19, scored goals at reserve and youth level but has struggled with injuries.

McAllister and Tonne have committed to the club until the summer of 2014, whilst Chapell and Adams have signed deals until the end of the season.

Manager Danny Wilson is delighted to have kept the services of these four young prospects, saying: "They have all done very well in training and are all continuing to develop as players. If they work hard they know that opportunities will come their way."

Meanwhile, Argentine defender Elian Parrino will be parting company with the Blades following a short spell at Bramall Lane.