Brinkley was drafted by the Vikings out of the University of South Carolina in the fifth round (150th overall) of the 2009 NFL Draft. As a rookie, he didn't see much time until E.J. Henderson suffered his devastating leg injury near the end of the season. He then started the final four regular season games, as well as both of the Vikings' pre-season contests.
Brinkley was again relegated to a backup role in 2010 with Henderson's return, but he was the starter in 2011 and 2012 for the Vikings at middle linebacker. He's always been much better as a downhill sort of linebacker, defending against the run, and was never really anything spectacular in coverage. That sort of linebacker appears to be a dying breed in the National Football League, and when the Vikings were re-signing their in-house free agents in the opening day of free agency, they seemed content to let Brinkley walk.
Best of luck to Jasper Brinkley going forward.