The 27-year-old follows Ade Akinbiyi and David Unsworth out of the Bramall Lane exit door, with the striker and defender respectively joining Burnley and Wigan last week.

Ifill played a key role in United’s promotion to the Premiership last season following his £800,000 (€1.2m) arrival from Millwall in the summer of 2005, scoring nine goals in 39 Championship appearances.

However, he has struggled to command a place in the United team this term, starting and playing in just three Premiership games, with his last appearance in mid-September.

Ifill has signed a two-and-a-half-year contract with the Eagles and leaves with Warnock’s best wishes as he said: “We’d like to thank him for his contribution in helping the club.”