Shawne Merriman Laughing, Joking, Smiling -- 'I'm Totally Fine!!!'

Shawne Merriman looked like a million bucks walking out of the gym today in L.A. -- completely laughing off rumors that he suffered from a drug overdose last night.

As we reported, the 29-year-old retired NFL star was transported from Colony nightclub to an L.A. hospital around 9:30pm Sunday night, following a 911 call reporting that he had possibly OD'd.

The caller said Merriman was "barely conscious" -- but just hours later, following his brief trip to the hospital, Merriman was back at the club looking like normal.