[4] It took until January 2010 for him to make his first-team debut, in a FA Cup third-round match at home to Barrow; he came on as a substitute late in the game which Sunderland won 3–0.

[9] Liddle signed a four-month youth loan with another League One club, Leyton Orient, on 5 August 2010,[10] but returned to Sunderland after only a month because of a groin injury.

[15][16] Liddle joined League Two club Accrington Stanley on loan for an initial month on 24 February 2012,[17] and made his debut the next day in a 2–0 loss against Swindon Town.

[20] He began the season as a regular in the starting eleven until 18 September, when the second sending-off of his Stanley career, just before Chesterfield scored a winning goal, resulted in a three-match ban.

[23] He appeared in the first five matches of the season before an ankle injury was to keep him out for two months;[24] he returned to the first team as a late substitute against Wycombe Wanderers.

[25] He lost his place to short-term signing Lee Naylor, and the rest of Liddle's season was disrupted by hamstring trouble and competition from Laurence Wilson.

[26] After signing on for a third year,[27] Liddle started the opening game of the season, but a "succession of niggling injuries" were to keep him out for three months.

He made his first-team return in the FA Cup first round, a goalless draw with Notts County in which manager John Coleman thought he was the best player.

He was a regular in 2020–21 before the National League North was abandoned because of COVID-19 pandemic-related issues,[38] and left the club at the end of that season.