Royals return for crocked Brett
Last Updated: September 22, 2011 6:28pm
Williams has only made one appearance for the Millers since making the temporary switch in August - coming off the bench in the 3-2 defeat to Swindon - but he will go back to the Don Valley Stadium once he has recovered.
"He's got a little niggle on his thigh so he's gone back to Reading for treatment," Rotherham boss Andy Scott told the club's official website.
"He understands he's got some competition in front of him and he's got to work hard and push for a place. He'll be back with us after the treatment."