Atlanta Hawks Star DeShawn Stevenson -- Accused of Stiffing Ex-Agent Nearly $200,000

DeShawn Stevenson's defensive skills are wearing thin ... because the Atlanta Hawks star has dodged a $190,000 bill from his ex-agent for almost a year, but now a judge has ordered him to pay the piper.

According to legal docs, Mark Barelstein claims he repped DeShawn since 2006 and brokered some massive deals for the NBA star -- specifically for the Washington Wizards in 2007 ($15 million), the Dallas Mavericks, AND the New Jersey Nets in 2011 ($2.5 million).

In January 2012, Mark filed docs claiming DeShawn failed to cough up the commission he was owed to the tune of $190,043.80. An arbitration court agreed and ordered the NBA star to pay up back in August.

But Mark says DeShawn STILL hasn't shown him the money, so he recently filed legal docs earlier this month in Georgia (where DeShawn lives and works) to have the judgment enforced there and start the process of collecting.