The Scotland international appeared seven times for the Robins, netting on two occasions, but after his loan ended, the player opted to return to the Molineux.
But his efforts did not go unnoticed by Johnson who was keen to keep him around in the Championship.
"We thank Chris for his time with us," he told the club's official website.
"There were a few factors. I had a chat with Mick and I think a lot of it was down to the player.
"Chris worked so hard getting to the Premier League and I think he wants to be there for the final weeks of the season.
"He wants to be with his family and try and see if he can win a place in the first team at the top level."