Oklahoma football coach Bob Stoops is retiring as head coach of the Sooners, effective immediately. Offensive coordinator Lincoln Riley will take over as the head coach of the program effective immediately.

Surprised? You should be, because it is not very often a head coach announces his retirement in June with a playoff caliber team ramping up for the upcoming season. The news was first reported by The Oklahoman on Wednesday afternoon, and it immediately sent shockwaves through the college football Twittersphere.

When something like this comes out of nowhere, there are a few questions that have to be asked. Is Stoops or Oklahoma under any NCAA or legal trouble? That does not appear to be the case. Second, is Stoops in good health? By all accounts, there appears to be nothing wrong with Stoops’ health.

At the moment, this simply appears to be Stoops stepping away from the high pressure job of being a college football coach, one that has caused him some frustration in recent years that has inevitably led to some wondering if he would look for a way out of Oklahoma, be it with another college football program or in the NFL. Stoops is young enough to suggest we should not rule out the possibility of seeing Stoops back on a sideline in the future (barring unforseen circumstances, of course), but it’s possible Stoops is just burned out and wants to relax.

In fact, that’s the rumored reasoning for his retirement – he just wants to live his life.

Stoops has been the head coach at Oklahoma since 1999 and reshaped the program as a true national title contender in that time. Stoops went 9-9 in bowl games and 190-48 overall. Along the way, Oklahoma won a BCS National Championship in 2000, 10 Big 12 titles, and made an appearance in the College Football Playoff and played for the BCS national title. The two-time Walter Camp Coach of the Year had been one of the top coaches in the game not named Nick Saban or Urban Meyer and didn’t give any indication he was ready to step out of the spotlight in Norman.

But, as Bruce Feldman of FOX Sports reports, this is a decision that appears to have been in the works for a while, as Stoops and Oklahoma Athletics Director Joe Castiglione were preparing Riley for just this moment.

Feldman also reports the 56-year old Stoops is simply ready to try something new. Stoops has multiple homes and has been around long enough ot know there are some moments in life you miss out on as you continue to coach. Whether Stoops is just ready to kick back and relax in retirement remains to be seen. He is certainly well off for years to come, considering the money Oklahoma had been paying him for the past 18 years. Stoops could also be a good fit on television, and he just became the hottest name on the TV free agent market for networks like ESPN and FOX.

So now, Oklahoma prepares for a promising 2017 season with a huge question mark on its hands. Is Lincoln Riley the kind of coach that can lead Oklahoma to a Big 12 title and make a national championship push? Riley, 33 years of age, has never been a head coach before, and he now takes over the top program in the Big 12 in a year that sees experienced coaches like Matt Rhule and Tom Herman come into the conference. Riley has the luxury of having the most talent to work with in 2017, but he will be tested early with his big game decision making. Riley’s Sooners take on Urban Meyer’s Ohio State Buckeyes in Columbus, Ohio in Week 2.

As the new head coach, Riley has a golden opportunity to prove he is worthy of being Oklahoma’s full-time head coach in the years to come, but if the Sooners struggle to meet some lofty expectations, Oklahoma has the funding to hire a big name head coach on the rise or pull from available options elsewhere. Chip Kelly is spending the upcoming season in the ESPN studio, for example, and nobody believes Kelly is going to stay in TV for long.

The future of Oklahoma football is up in the air heading into 2017, and that is something nobody expected to be saying at this point in time.

[This article originally stated Lincoln Riley was going to be the interim head coach, but Oklahoma confirmed Riley will be the full-time head coach moving forward after this post was published.]

About Kevin McGuire

Contributor to NBCSports.com's College Football Talk, Athlon Sports and The Comeback. Host of the No 2-Minute Warning Podcast on iTunes, Stitcher Radio and iHeart Radio. FWAA member and Philadelphia-area resident.