Nelson will assist hitting coach Derek Shelton and work with the club's catchers, but he will not be in uniform during games.
Nelson, 52, has spent 29 seasons in professional baseball, 17 of which have been spent as a manager or coach. He joined the Rays on Jan. 1, 2000.
Nelson has spent the past five seasons as the Rays' catching coordinator. Prior to that stint, Nelson managed Rookie-level Princeton for five seasons.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.