NBA's Thabo Sefolosha -- Too Injured to Attend Playoff Games ... 'It's Killing Him'

ATL Hawks forward Thabo Sefalosha hasn't been able to attend a SINGLE playoff game due to the injuries he suffered during an altercation with the NYPD and he's "devastated" ... sources tell TMZ Sports.

As we previously reported, Sefalosha claims he broke his right fibula and sustained ligament damage as cops tried to take him into custody following a stabbing outside of a nightclub last month.

Thabo underwent surgery ... and sources tell us he's basically been relegated to his home to rest and recover ever since .... while his teammates have been tearing it up in the NBA playoffs.

"It's killing him that he's not in the playoffs," one source close to Thabo tells us ... "He'd much rather be competing with his team."

Meantime, Sefalosha is still facing criminal charges from the night of the arrest -- obstruction of a police officer and disorderly conduct -- though we're told he's still fighting the case ... and expects to be vindicated.