Yorke made his Blues bow in an unaccustommed left midfield role but the Blues boss said he had no alternative but to play the former Villa, Manchester United and Blackburn Rovers striker there because of injuries.
"Its not his natural position, we know that, but it was a bit of a neccessity because we've had to shuffle around because of injuries," the Blues boss said.
"Dwight's played there for Villa in his younger days and with Clapham, Lazaridis and Dunn missing we're a bit short on that side.
"So with the injuries we just had to put him in an unfamiliar position.