Steve Kirby: released at his request © Getty Images

Yorkshire have released Steve Kirby, the right-arm fast bowler, at his own request.

Kirby, 26, played a crucial role in Yorkshire's Championship-winning season of 2001, taking 47 first-class wickets at just over 20 apiece. This performance earned him a place in the first England Academy squad which left for Australia in November 2001.

But he has since struggled to produce the same form. In 2004, he claimed only 31 wickets at an average of more than 36, after suffering with a niggling back problem.

A statement from Yorkshire explained: "David Byas, director of cricket, and the board with great reluctance have agreed to this request and it is effective immediately. The Yorkshire County Cricket Club sincerely thank Steven for his efforts over the last four years and wish him every success in the future."