Cavaliers forward Kevin Love left Tuesday night's 109-101 loss at the Atlanta Hawks with back spasms.
Love went to the locker room after exiting with just over a minute remaining in the third quarter. Cleveland later announced that he would not return to the game.
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Love scored seven points on 1-for-8 shooting and grabbed seven rebounds in 24 minutes. The 26-year-old has averaged 17.1 points and 10.2 rebounds over 30 games.
Love, who has dealt with back spasms in the past, has not missed a game in his first year with Cleveland following a summer trade from Minnesota involving 2014 top NBA draft pick Andrew Wiggins.
On Tuesday, The Cavaliers were playing without star forward LeBron James, who sat out due to left knee soreness. Cleveland dropped to 18-13 while Atlanta improved to 23-8.
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The Cavaliers, which host the Bucks (16-16) on Wednesday, have lost three of their last four games and are now in fifth place in the Eastern Conference standings.