Michael Higdon and Connor Dimaio have been released, with both contracts cancelled by mutual consent.



Signed by previous manager Nigel Clough in the summer of 2014, Higdon made a total of 24 appearances for United, scoring five goals.



Meanwhile, Dimaio, who was a regular with United's U21s, made his league debut at Crawley Town in March 2014 and leaves Bramall Lane having made five senior appearances.