The Oakland Raiders will start their first playoff game since 2002 with a third-string quarterback and backup left tackle.
Penn suffered the injury late in the Week 17 loss to the Denver Broncos. He sat out all practice all week.
Saturday's absence will mark the first missed game for the 33-year-old in 10 seasons, since he took over the starting gig in Tampa Bay in 2007. Penn played in 160 consecutive games, per NFL Research. Penn has been one of the top left tackles in the NFL all season, particularly in run blocking.
The news is troubling for rookie Connor Cook, making his first career start. In relief last week, Cook showed a big arm and ability to get through his progression, traits he displayed during his career at Michigan State. However, Cook turned the ball over and for stretches looked every bit a lost rookie with few practice snaps under his belt.
A heretofore fantastic offensive line is banged up at the worst possible time. Oakland allowed the fewest sacks (18) in the NFL this season. The Raiders ranked sixth in the NFL with 120.1 rush YPG and 11th in rush yards before contact (2.4) in 2016.