Patrick completed a three year scholarship at Manchester United before signing a professional contract. Although joining as a creative midfielder, he became something of a utility man and his ultimate position is still to be determined. In 2012/13, due to defensive injuries, he played as a centre back and although still classified as a midfielder, it was at centre back where he's found opportunities in 2013/14, forming a successful make-shift pairing with Charni Ekangamene. He scored a last minute winning goal away at Reading in the Under-21 Premier League which took Manchester United through to the league semi-final playoffs.
Patrick was included on the bench for the first team for the first team away to MK Dons in the 2014/15 League Cup 2nd Round defeat but was unused. With the first team obliterated by injuries, McNair made his debut at home to West Ham on 27th September and continued to be involved with the first team, covering a number of positions.
In 2015/16 he found opportunities hard to come by and in August 2016 he was sold to Sunderland for a fee of £5m. He signed a four year contract with the club.