Buccaneers defensive end Jacquies Smith is on a visit to the 49ers, a source tells Ian Rapoport of NFL.com (on Twitter). Smith is a restricted free agent, so the Bucs reserve the right to match any offer sheet. 
Smith was given the original round/right of first refusal tender by Tampa Bay this offseason. Because he entered the league as an undrafted free agent in 2012, the Buccaneers would not receive any draft compensation if they allowed an offer sheet to go unmatched.
Smith, 27, compiled 13.5 sacks between the 2014 and 2015 seasons. He suffered a torn ACL last season, but he is almost fully recovered, according to Rapoport. He was the only Tampa Bay defensive end with more than five sacks in 2015 and the team’s decision to give him the lowest level tender came as a bit of a surprise.
The Bucs currently project to start Robert Ayers and William Gholston at the defensive end spots. Beyond those two, they have Noah Spence, Davonte Lambert, and three other defensive ends under contract, not including Smith.
The Niners, meanwhile, have Arik Armstead and Aaron Lynch at defensive end with Ronald Blair and Zach Moore in support. If healthy, Smith could give them a big boost on the defensive line.