As Rapoport noted Wednesday, the deal "should be done this week. He showed up, they kept their word."
Penn, 34, ended his holdout Aug. 23, and Rapoport reported at the time that the Raiders wanted him to return to the team before negotiating an extension.
Penn will make $5.8 million for the 2017 season and is certainly due a significant raise. Sam Monson of Pro Football Focus ranked him as the No. 86 player in all of football in 2016, writing that he was "a dominant run-blocker all season, destroying people that got in his way and allowing just four sacks or hits on the QB."
As for comparable salaries to what Penn could expect, Conor Orr of NFL.com wrote, "[Philadelphia] Eagles right tackle Lane Johnson is the league's 10th-highest-paid tackle at $11,252,000. Los Angeles Rams tackle Andrew Whitworth is right behind Johnson at $11,250,000. The Raiders paid guard Kelechi Osemele an average of $11.7 million, while fellow guard Gabe Jackson recently inked a deal worth $11 million per year."
While there may be some concern about Penn's age, the reported two-year duration of the extension should mitigate some of those worries. Plus, the left tackle has shown little indication of slowing down and was one of football's best tackles last season. His ability to keep Derek Carr upright and protect his blind side is highly valuable for an Oakland team with legitimate Super Bowl aspirations this season.