Harris, 30, had originally hoped to be cleared to play in December, but he suffered a setback in his rehabilitation. He returned to full-contact practice last week and was cleared to make his season debut Saturday night against the Portland Trail Blazers.
"It's been a long time," said Harris, who the Mavs plan to eventually use as the primary backup at both guard positions. "I'm just excited to get back out there. I've obviously been watching a lot and words can't describe it. You miss it so much being gone for so long. I'm just nervous and ready to get it going."
Harris, a nine-year veteran in his second stint with the Mavs, originally agreed to a three-year, $9 million deal to return to Dallas in July. The parties mutually agreed to take the deal off the table after a pre-signing physical revealed he needed surgery to repair the second metatarsal on his left foot. He eventually agreed to a one-year deal for the veterans minimum.
The toe bothered Harris for much of last season, when he averaged 9.9 points and 3.4 assists in 58 games for the Atlanta Hawks.
The Mavs anticipate Harris, who has averaged 12.8 points and 4.9 assists during a career that has also included stints with the Nets and Jazz, will add athleticism and experience to their backcourt rotation. His presence also addresses the Mavs' need for improved backcourt defense.
Coach Rick Carlisle said he won't have a strict minutes restriction for Harris, but he will cautiously monitor the guard.
"We're definitely excited to have Devin back," Mavs owner Mark Cuban said. "We're not expecting miracles. He's got to get back playing. It's been a while for him. It's not going to happen overnight, but this is definitely a step in the right direction."