Mattie McKiernan

Legspinning allrounder Mattie McKiernan was brought in for a senior debut at 24 after impressing Derbyshire's T20 coach John Wright with his performances in the seconds. He only played once in the 2018 season but won a place on the staff and made a first-class debut the following summer.

His breakthrough came in 2022, when he played every match as Derbyshire reached the T20 Blast quarter-finals - although he collected an unwanted record in that match at Taunton, as McKiernan's four-over spell of 0 for 82 became the most-expensive analysis in T20 history. He also scored a maiden first-class hundred, against Leicestershire at Grace Road, to help set up an innings win.
ESPNcricinfo staff