Cramlington-born defender Liam has been with Sunderland since the age of 12.
The combative right-back started his fledgling career with Cramlington Juniors before being snapped up by the Black Cats.
Along with John Egan, Liam was made joint captain of the youth team by coach Kevin Ball for 2010-11.
He played 29 games as the young Cats secured the league title, adding a further nine appearances for the reserves.
Liam joined the club's development squad as a professional ahead of the 2011-12 season and started a team-high 19 games, adding a further three appearances as a substitute.
The youngster continued to impress for the development squad in the 2012-13 campaign, playing 20 times before he was called up to first-team match day squads for the games against Everton, Stoke, Southampton and Tottenham Hotspur.
He also finished the 2012-13 season as the development squad's captain.