[3] Throughout training camp, Bynes competed for a roster spot as a backup linebacker and special teams player against Tavares Gooden, Jason Phillips, Anthony Leon, and Chavis Williams.

On September 1, 2011, Bynes received an opportunity to play in the Ravens' preseason finale and recorded six solo tackles and two sacks in their 21–7 victory at the Atlanta Falcons.

On November 9, 2011, the Baltimore Ravens signed Bynes to their practice squad after linebackers Ray Lewis and Dannell Ellerbe sustained injuries.

On November 29, 2011, the Baltimore Ravens officially released Bynes after Ray Lewis recovered from his toe injury and re-signed him to their practice squad.

[3] During training camp, Bynes was expected to compete for a roster spot as a backup inside linebacker against Brendon Ayanbadejo, Ricky Brown, Darryl Blackstock, and Nigel Carr.

Bynes sustained a cracked vertebrae during the beginning of training camp during a goal line scrimmage and was expected to miss four or five weeks.

[11] On October 17, 2012, the Ravens added Bynes to the active roster after Ray Lewis tore his triceps and was placed on injured reserve for the remainder of the regular season.

Upon joining the active roster, Bynes was named a backup inside linebacker behind Dannell Ellerbe and Jameel McClain.

[12] On December 16, 2012, Bynes earned his first career start and recorded a season-high 13 combined tackles (11 solo) and deflected a pass during a 34–17 loss to the Denver Broncos in Week 15.

Bynes was named the starting inside linebacker after Jameel McClain suffered a spinal cord contusion during the Ravens' Week 14.

[17] Bynes entered training camp slated as a starting inside linebacker after Ray Lewis announced his retirement and Dannell Ellerbe departed in free agency.

Bynes was inactive for the Ravens' Week 7 loss at the Pittsburgh Steelers due to thigh injury and infection in his finger.

[26] Bynes was reunited with Detroit Lions' head coach Jim Caldwell who was previously the offensive coordinator with the Baltimore Ravens.

Bynes finished the 2015 season with a career-high 82 combined tackles (56 solo), five pass deflections, and was credited with half a sack in 16 games and 11 starts.

[40] Throughout training camp, Bynes competed for a job as a starting inside linebacker against Haason Reddick, Scooby Wright, Zaviar Gooden, and Philip Wheeler.

[41] Head coach Bruce Arians named Bynes a backup inside linebacker to begin the regular season in 2017, behind Deone Bucannon and Karlos Dansby.

On December 10, 2017, Bynes recorded a solo tackle, deflected a pass, and made his first career interception in the Cardinals' 12–7 win against the Tennessee Titans in Week 14.

Bynes made his second career interception off a pass attempt by Titans' quarterback Marcus Mariota, that was originally intended for tight end Delanie Walker, and returned it for a 25-yard gain in the fourth quarter.

[43] On December 17, 2017, Bynes recorded two tackles before exiting in the fourth quarter of the Cardinals' 20–15 loss at the Washington Redskins due to an ankle injury.

Bynes entered training camp slated as the starting middle linebacker, but saw minor competition for the role from Scooby Wright.

[51] Four days later, during a week 5 game against the Pittsburgh Steelers, Bynes intercepted a pass thrown by running back Jaylen Samuels in the 26–23 win.