Bieniemy has interviewed for several head coaching positions over the last few years, most recently with the Denver Broncos. However, he has not been hired for one.
As Kansas City built up a 21-3 first-half lead against the Bengals in today's AFC Championship Game, Manziel tweeted his thoughts on Bieniemy.
"How Bieniemy isn't a head coach in the league blows my mind," Manziel said.
Manziel is far from the only person to ask this question. Bieniemy has been a head coaching candidate numerous times but no one has given him the opportunity to take over his own team yet.
For now, he'll continue to be an integral part of the Chiefs' success as they try to wrap up a third-straight trip to the Super Bowl.