Ray Rice returned to his old stomping grounds on Thursday ... but he wasn't the only former star running back hanging out on the Baltimore Ravens sidelines -- he was spotted chopping it up with Marshawn Lynch.
The Super Bowl champion -- who has made several appearances at Ravens events after getting kicked off the team in 2014 -- was a popular guest at training camp hours ago ... with kids flocking to him after he arrived.
RR appeared to be in great spirits throughout the visit .