Dwight Howard Knows Lakers Gig is 'Last Chance,' Says Matt Barnes

L.A. is Dwight Howard's final shot at returning to NBA dominance and he knows it ... so says Matt Barnes, who tells TMZ Sports it's "time to put the bullsh*t to the side" and get back to business.

Of course, it's been over 6 years since Howard's disastrous first stint with the Lakers ... and the guy's career has never been the same.

So, when we spoke with Barnes -- who played with Howard on the Magic in 2009 and 2010 -- about the reunion in L.A. ... he says it could be a new spark in Dwight's career.

"I think he realizes it's his last chance and really need to put all the bullsh*t to the side and just go out there and play basketball," Barnes says.

For his part, Howard says that's exactly what he's trying to do -- even attempting to shut down a beef with Shaquille O'Neal because he wants to focus on basketball.

Of course, Dwight has been considered a disruption in the locker room for most of his career. We asked Barnes if that was a fair rap.