According to ESPN's Adrian Wojnarowski, Boston Celtics guard Marcus Smart will undergo thumb surgery today.  The surgery, which is being performed to repair a torn ligament, is expected to sideline Smart for some time, though there is apparently hope that the defense-first guard will be back during the postseason.

In his weekly spot on 98.5 The Sports Hub's "Zolak & Bertrand" show, Celtics head coach Brad Stevens addressed the fact that Smart's injury, which he suffered in the team's Sunday loss to the Indiana Pacers, could sideline him long term and potentially for the remainder of the season.

Smart, who provides high level defensive play and the potential to score at a solid clip on any given night, missed time earlier this season with an injury to the same hand.

That injury was caused by an off-court incident in which the veteran cut his hand swinging at a picture frame.

Early reports do not link the ligament issue, now requiring surgery, to that previous injury.

The C's scuffled defensively without Smart, earlier this season. Having the veteran, bull dog on the court during the stretch run and at least part of the postseason could severely hinder Boston's chances at making a run at a trip to the NBA Finals.