The guard bent his right wrist back in the first quarter of the team's 110-82 defeat to the San Antonio Spurs.
After the game, Coach Larry Drew told reporters: "The X-rays were negative, which is a good sign. Right now it looks like he's in a splint and I don't know how long he will be out.
"It swelled right away, as soon as he did it and that was a big concern. I guess we'll go back and I believe he'll get an MRI."
Ridnour added two points in an 11-minute spell before being forced off with the injury.