Now entering this season at the age of 30, Penn is at the stage of his career in which his level of play needs to stay in order to maintain his spot on the team. Penn is due $6.4 million next season and there reportedly have been concerns about Penn's work ethic in the past.
"Penn loves playing for the Buccaneers and is one of those locker room guys that coaches love to have, but also has an occasional lazy streak and has failed to meet most of the weight clauses in his most recent contract, which also drives management crazy," Mark Cook of PewterReport.com wrote Sunday.
Penn was inherited by coach Greg Schiano's staff, which has emphasized sticking to a closely managed program. As naturally talented as nearly any left tackle, Penn's quality of play has gone up and down at times over the past few years.
We get the sense this is a transition year for the Buccaneers in many ways. Guys like quarterback Josh Freeman, Penn and even receiver Mike Williams have to prove their long-term worth to the franchise.
Follow Gregg Rosenthal on Twitter @greggrosenthal.