The 26-year-old suffered multiple dislocations around his right thumb after being hit during a Mercantile tournament match.
According to ESPNcricinfo, the recovery period for the injury is expected to be three weeks, with Sri Lanka team management hoping to see Chandimal fit for the upcoming tour to Zimbabwe.
The schedule for the tour is yet to be decided, but the first Test is likely to commence on October 29.
The vice-captain has been in prolific form this year, notching up a total of 1451 runs from 36 matches he played across formats.
Chandimal, who stood in as captain for injured Angelo Mathews during a part of the ODI and T20I series against Australia, also struck five successive ODI half centuries between June and August this year.
He, however, missed out on becoming the first Sri Lanka batsman to score six consecutive fifties when he got dismissed for 48 in the second ODI against the Steve Smith-led side.
Image: Dinesh Chandimal