The winger had been on loan at Carlisle and has now terminated his contract with the Sky Blues so that he is free to go to America.
Birchall joined City from Port Vale in the summer of 2006 and had seventeen starts with eleven appearances as a sub. He had a League Cup start and a substitute appearance in the FA Cup and scored goals against Norwich at home and Plymouth away.
Birchall in action for City Reserves
The Trinidad & Tobago international was also an integral part of the City team which won the Birmingham Senior Cup. He scored at Stourbridge in Round Four and against Walsall in the Final.
All at Covsupport News Service wish him well.