Roy Jones Jr.'s Gone Fishin' But Ain't Done Boxing

Roy Jones Jr. has a message for the boxing world ... I AIN'T DONE JUST YET!!

Less than a month after tearing his right bicep fighting Rodney Moore -- and saying the injury may end his career -- Jones Jr. tells TMZ Sports he feels great and is eyeing a return to the ring.

"I'm doing much better. My arm feels good."

In fact, Roy felt good enough to catch some big fish in Pensacola, Florida this weekend (Roy says he caught a shark) ... albeit while rockin' a big arm brace.

So, when does 47-year-old RJJ anticipate a return to the squared circle?