The Mavericks are thin at point guard as Dominique Jones made just his third career start for the team Wednesday night against the Chicago Bulls because starter Darren Collison has a sprained right middle finger.
The position has been a bit of a concern for the Mavericks in the early going as Collison has struggled at times.
"Right now, the point guard position is a challenge for us," coach Rick Carlisle said Wednesday. "I think Derek can help us."
Fisher, 38, averaged 5.6 points and 2.7 assists in 63 games with the Los Angeles Lakers and Oklahoma City Thunder last season. He had a more expanded role in the Thunder's playoff run, averaging 6.3 points and 22 minutes per game. This will be his 17th season.
The Mavericks, who had 15 guaranteed contracts, released forward Troy Murphy to create a roster spot for Fisher.
Information from ESPNDallas.com's Tim MacMahon was used in this report.