Diskin is a product of amateur rugby league club Dewsbury Moor ARLFC and growing up he attended St. John Fisher High School in Dewsbury, as did Francis Cummins and Ryan Sheridan.
2010 saw Diskin celebrate his testimonial year at Leeds after ten years of service to the most successful club of recent years. Diskin had been instrumental in all of Leeds' championship winning campaigns. He played in the 2010 Challenge Cup Final defeat by Warrington at Wembley Stadium.[23][24]
On 19 October 2010, it was announced that Diskin had agreed a move to Bradford on a three-year contract, and was expected to push for the starting hooker position in the Bradford line-up.
Bradford Bulls
Diskin appeared in two of 2011's four pre-season games. He played against Dewsbury and Wakefield Trinity. Diskin featured in 23 consecutive games from Round 1 (Leeds) to Round 23 (Warrington). He also appeared in the Challenge Cup game against Wigan. He scored against Leeds, Crusaders and Harlequins RL. A shoulder injury kept him out for the rest of the season.
Diskin featured in 2013's pre-season friendlies against Dewsbury and Leeds. He scored against Dewsbury (1 try). He featured in four consecutive games from Round 1 (Wakefield Trinity) to Round 4 (St. Helens). He missed Round 5 due to injury. He returned for Round 6 (Widnes) but was ill for Round 7. Diskin returned for Round 8 (Catalans Dragons) to Round 9 (Leeds). He missed Round 10 due to an injury. Diskin featured in Round 11 (London Broncos) to Round 16 (Huddersfield). He returned to the team for Round 18 (St. Helens) to Round 27 (Huddersfield). Diskin also appeared in the Challenge Cup against London Broncos. Matt scored against Widnes Vikings (1 try), Salford City Reds (1 try) and Hull F.C. (1 try). Diskin signed a one-year extension to his contract midway through the season.
Diskin was put in temporary charge of the Bradford outfit on 16 June 2014 as a player coach. It was the day following the sacking of head coach Francis Cummins, and assistant Lee St Hilaire. Diskin took charge of Bradford's home match against Hull Kingston Rovers where they lost 44–18 the Tuesday after James Lowes was announced as Bradford's new head coach.
At the end of the 2014 season, Diskin announced his retirement.[25]