Liam Cooper
Signing from Chesterfield, Liam Cooper, penned a three-year contract at Elland Road for an undisclosed fee in August 2014.
Cooper caught the eye for the Spireites in a 2-2 pre-season friendly draw against his future employers and within a matter of weeks he made the switch to West Yorkshire.
The 23-year-old centre-back, who is predominantly left-footed, was part of Chesterfield's League Two-winning squad the previous season after joining permanently from Hull City in January 2013.
He made his United debut in August 2014's 1-0 win at home to Middlesbrough and scored his first goal for the club in the following November's 3-1 win over Blackpool.
Cooper kept his place in defence and was handed the captain's armband for the first game of 2015 - the FA Cup trip to Sunderland.
Despite being born in Hull, Cooper has been capped at Under-17 and Under-19s level for Scotland.