The Mavs do not believe the injury is serious. Harris is questionable for Wednesday night's game against the Utah Jazz.
"I would not rule it out," Harris said. "We'll just see how it feels tomorrow and then make a decision."
Harris, the primary backup at both guard positions, started feeling soreness in the Achilles during last week's loss to the Denver Nuggets. He got treatment the next day and had two of his best games of the season over the weekend, averaging 16 points on 66.7 percent shooting in wins over the Portland Trail Blazers and Indiana Pacers and coming up with clutch buckets late in both games.
Harris, who missed the first half of the season while rehabilitating from summer toe surgery, felt soreness again before Tuesday's game and left after playing less than seven minutes.
"I still wanted to give it a go," said Harris, who is averaging 7.9 points and 4.0 assists in 18.5 minutes per game this season. "It just wasn't feeling right, so just didn't want to risk it. ... It wasn't anything specifically that I did. It just flared up."