Wells was forced to limp off midway through the first half during Saturday's dramatic last-grasp win over Shrewsbury Town after receiving a kick from Shrews defender Dave Winfield as the pair contested for the ball.
The scan on Wells' injured left ankle seems to suggest that the problem isn't too severe, but early estimates would indicate that the Bermudian will still be out for at least the next couple of weeks.
Bantams boss Phil Parkinson explained: "The scan showed there was nothing really serious. Nahki has some ankle ligament damage.
"He will be out for most probably at least a couple of weeks but we will know more once the swelling has gone down."
Although Wells is likely to be missing for Saturday's Sky Bet League 1 fixture at Walsall's Banks's Stadium, team-mate Rory McArdle should be back in contention for the match after making a return to the training ground this Tuesday.
McArdle had missed Saturday's win over Shrewsbury and this Monday's training due to illness, but the defender was back at Apperley Bridge with the squad today.
McArdle will now be hoping he can prove his fitness in time for Saturday's trip to Walsall, with Gary Jones (hamstring) and Garry Thompson (Achilles) looking to do the same after the pair reported minor injuries during the week.
Pictures provided by Gary Chadwick