[8] On March 18, 2016, Brown attended Akron's pro day, and decided to run all of the combine drills again for team representatives and scouts.
[20] Throughout training camp, Brown competed for a job as a backup inside linebacker against Nick Dzubnar, Perry, and James Ross.
[23] Head coach Mike McCoy named Brown the backup inside linebacker behind Denzel Perryman and Manti Te'o to begin the regular season.
[24] He made his professional regular-season debut in the Chargers' season-opener at the Chiefs and recorded three combined tackles and a pass deflection during a 33–27 loss.
On September 25, 2016, Brown collected six combined tackles, two pass breakups, and made his first career sack on Colts quarterback Andrew Luck during the Chargers' 26–22 victory.
[25] On October 2, 2016, Brown earned his first career start after Manti Te'o suffered a torn Achilles tendon during the Chargers' win in Indianapolis.
In Week 6, he collected a season-high 14 combined tackles (13 solo), forced a fumble, and made his third career sack in the Chargers' 21–13 win against the Denver Broncos.
[27] On December 24, 2016, he made ten combined tackles and also recorded a sack on Robert Griffin III with teammate Kyle Emanuel as the Chargers lost at the Browns 20–17.
[36] Hayes Pullard and Korey Toomer had an advantage over the other linebackers as they both previously played under first year defensive coordinator Gus Bradley in Jacksonville Jaguars and Seattle Seahawks and also had an established relationship with him.
[37] Brown saw his defensive snap count decrease dramatically after Perryman returned and Week 10 and was moved to starting weakside linebacker.
He was also replaced as the dime linebacker, as defensive coordinator Gus Bradley opted to go with safety Adrian Phillips when the offense had three or more wide receivers on the field, which was 64% of the time.
He suffered an ankle injury in Week 17, missed the Chargers wild-card win over the Baltimore Ravens, and was placed on injured reserve on January 7, 2019.