TAMPA — The Bucs will begin free agency by signing defensive tackle Beau Allen, a key cog in the Philadelphia Eagles No. 1 run defense.Allen, a seventh-round pick out of Wisconsin in 2104, had 20 tackles 423 defensive snaps as a rotational player for the Eagles, who allowed a league-best 79.2 rushing yards per game.Allen reportedly agreed to a three-year contract worth $15-million that could increase to $16.5-million with incentives.The Bucs are thin at defensive tackle, aside from six-time Pro Bowler Gerald McCoy. Chris Baker, a big free agent signing a year ago, was released after only one season. Clinton McDonald is an unrestricted free agent.Pro Football Focus says Allen had the highest percentage of run stops of any free agent. He also had two tackles in the Eagles Super Bowl LII victory over the Patriots.The 6-foot-3, 327-pound Allen played four seasons with the Eagles and has two career sacks. He became difficult for the Eagles to hang on to since they have $28-million per year wrapped up defensive tackles Timmy Jernigan and Fletcher Cox.The Bucs also may be looking to shake up their offensive line. Ravens center Ryan Jensen is expected to visit the Bucs and Colts, according to Peter Schrager of NFL.com.Should the Bucs be able to land Jensen, it would mean moving Ali Marpet from center back to guard.