Cleveland Cavaliers guard J.R. Smith will need surgery on a right thumb injury sustained in Tuesday's overtime win against the Milwaukee Bucks.

Smith left the game in the first half with the issue, and, after on-site examinations at half-time proved inconclusive, he did not return.

The guard on Wednesday underwent further tests in Cleveland and a fracture to the right thumb that would require surgery was detected.

Smith, who signed a reported four-year contract worth US$57 million in October, has already has missed five games because of two separate injuries.

Although the Cavaliers gave no timeframe for his return, it is believed that he could be facing four to six weeks on the sidelines.