The Oakland Raiders have put together one of the strongest offensive lines in the NFL, and while there are many key young pieces of the group, a name that often seems to go overlooked is Donald Penn. While Penn is certainly the veteran of the bunch at age 34, he's proven capable of shutting down some exceptional pass rushers in recent seasons.

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If you don't believe it, just look at the following stat from Pro Football Focus, which shows that he allowed only one sack all last season, even while facing players like Brian Orakpo, Joey Bosa, Tamba Hali, DeMarcus Ware and Jadeveon Clowney.

After such a strong season, it prompted Penn's name to pop up on a list from For The Win's Steven Ruiz of the most underpaid players in the NFL.

4. Donald Penn, LT Raiders 2017 Cap hit: $7.15

Position rank: 19th Penn is one of the anchors on the league’s best pass-blocking unit. He allowed just one sack in 2016 over 16 games. One sack! It was a costly sack though, as it resulted in a season-ending injury for Derek Carr. That doesn’t change the fact that Penn is vastly underpaid. He’s an elite tackle being paid like a below average one.

It's hard to argue with the points made, but with that said, Penn is only under contract through 2017 and will be 35 next offseason. It's going to be interesting to see what his market looks like and what type of deal he could potentially land after the coming season.