As a senior, Brinkley captured All-Southeastern Conference (SEC) first-team honors as he started all but 1 game for the Gamecocks and ranked 2nd on the squad with 73 tackles.

[9] His spot on the depth chart was confirmed when Henderson went down with an injury to his femur after a collision with teammate Jamarca Sanford in week 13 at Arizona.

Brinkley stepped into the game in the fourth quarter, recording five tackles for negative 4 yards on Arizona running back Tim Hightower.

Brinkley has had a very close, apprentice-like relationship with Henderson who mentored him as a rookie throughout training camp and his first professional season, even quizzing him while watching film together.

On December 28 against the Chicago Bears, the Vikings suffered a crushing 36–30 overtime loss - their second in a row to a team that was not in playoff contention.

[citation needed] On March 12, 2015, Brinkley signed a two-year deal with the Dallas Cowboys, as insurance in case the team couldn't re-sign Rolando McClain.

Even though his contract included $2 million guaranteed in earnings, he was released on September 7 to make room for offensive tackle Jordan Mills.