Since then, Sheffield has been in the BBC medical drama series Holby City where he played Alex Adams from 2000 to 2003, as well as Lancelot in the 1998 television drama Merlin. He had a supporting role in the 2005 film The Wedding Date alongside Debra Messing and Dermot Mulroney. Subsequently, he made a cameo appearance in the final episode of Green Wing, playing a character that Sue White (played by Michelle Gomez) was dating.
