NBA player faces suspension for low blow

A basketball player could face a lengthy suspension after delivering one of the nastiest fouls in sport – a blow to the crown jewels – to a rival opponent in the NBA.

Boston Celtics player Marcus Smart left little to the imagination when he was caught on camera swinging his right arm into the groin of San Antonio Spurs' Matt Bonner.

Footage of the incident shows Smart trying to chase down Australian star Patty Mills early in the fourth quarter when he's blocked by a screen set by the sizeable Bonner.

Refusing to dodge the 208cm center, Smart runs straight at Bonner and, with a clenched fist, connects with a swinging arm to his lower midsection.

Remarkably, Bonner either didn’t feel the hit or masked the pain and was able to square up to the smaller Smart.

However, players and officials were able to get between the two players before tensions boiled over with the umpires ejecting Smart from the game.

US media is now speculating the ugly act could see Smart fined and served with a lengthy suspension by the NBA.

The Spur eventually ran out winners 101-89.