Fat Joe turned Yankee Stadium into a concert prior to Game 3 of the World Series ... but his performance might've resulted in more work for the grounds crew -- 'cause the rap legend rocked Timberlands on the mound.
The Bronx native hit the diamond and put on a show before first pitch ... with renditions of "New York" and "All The Way Up."
Joe sported a Yankee cap and jacket for the mini-set ... but what also caught people's attention was what he was wearing on his feet as he made his way to the bump -- with some folks worried about potential damage to the dirt ahead of the contest.