As a senior, he was named second-team All-Big Ten Conference, leading the team in pancake blocks (48) for the second straight year.
In 2008, he saw his first NFL action, playing in Games 2–6 on special teams, but was placed on Reserve/Injured list Oct. 17 due to a dislocated toe suffered in a collision during pregame warmups Oct. 5 against the Dallas Cowboys.
In 2009, he earned the starting position in preseason, and was praised by coaches as the “glue” of a revamped unit as the Bengals captured the AFC North title.
He helped lead fourth-quarter drives of 85 and 71 yards during a comeback win September 27 vs. the Pittsburgh Steelers.
On October 11 at Baltimore, Cook and the rest of the offensive line helped Benson become the first player in 40 games to rush for 100 yards against the Ravens, and on October 25 Benson rushed for a career-high 189 yards vs. the Chicago Bears while aiding a sack-free performance up front.
In 2010, he contributed to the Bengals ranking second in the AFC and sixth in the NFL in fewest sacks allowed per passing play.
The offensive line allowed no sacks for 100 straight passing plays to close the season, including the last three full games.