Josh Heupel speaks about his deep-rooted respect for the Oklahoma program and Tennessee's intention to spoil College GameDay in Norman.

After a 40-6 loss to Clemson in the Russell Athletic Bowl, coach Bob Stoops called longtime assistant Cale Gundy.

Stoops asked Gundy to meet him at Bison Witches in downtown Norman.

There, Stoops told Gundy he was going to fire his offensive coordinator, Josh Heupel.

The Sooners had just suffered through their worst season under Stoops.

TCU and Kansas State upset them.

Baylor blew them out.

And Oklahoma State, propelled by Tyreek Hill's punt return, rallied to win a Bedlam overtime thriller.

Then, in the bowl game, Brent Venables' Clemson defense shut down the Sooners in a humiliating defeat.

'Bob had to make a change,' Gundy recalled.

'I don't know, it was tough.

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it wasn't just struggles on the offensive side.

But Bob had to make that decision.

An unbelievably tough call.

'Heupel was—and remains—OU royalty.

In 2000, he quarterbacked the Sooners to their seventh national championship; OU hasn't won a title since.

Heupel later proved to be a valued assistant during the Sooners' prolific run through the 2000s.

He mentored Heisman Trophy-winning quarterbacks Jason White and Sam Bradford.

In 2011, Heupel became offensive coordinator, and over the next four seasons, OU averaged 475 yards per game, 10th-best in college football during that span.

But in 2014, Stoops realized that his Sooners needed a spark.

And so, shortly after meeting Gundy, Stoops fired Heupel, later calling it the 'worst day' in his 18 years as OU's coach.

'I have this deep appreciation for Josh, certainly first and foremost as a player,' said Venables, OU's coach now and its co-defensive coordinator when Heupel starred for the Sooners.

'I've always looked back and said, 'Man, we couldn't have done it without Heupel.

' His leadership, what he was able to do from a transformation standpoint to our locker room, the guts and the toughness that he played through.

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I've always held him up here on this pedestal, from a player's standpoint.

'Saturday, for the first time since the firing, Heupel returns to the stadium where he became a Sooners legend.

In his fourth season at Tennessee, Heupel brings the surging sixth-ranked Volunteers to Norman for OU's long-anticipated first conference game as a member of the SEC.

Heupel has downplayed the significance of the reunion.

He has also avoided opening up about the firing.

Heupel said Monday that he was 'tremendously grateful' for the opportunity OU gave him, both as a quarterback and a coach.

'I hope enough time [has gone by] that he still understands how much he means to this state, how much he means to the program,' Bradford said.

'I hope that he gets a warm reception.

I hope that he's able to appreciate that and take that in before the game gets going.

'In 1999, months after Stoops took over a struggling OU program that had reached an all-time low.

Since the end of World War II, the Sooners had boasted more victories (443) than any other school.

But OU hadn't enjoyed a winning season since 1993.

Stoops hired Air Raid guru Mike Leach from Kentucky to call plays.

Immediately, Leach went searching for a quarterback.

He ended up targeting an unknown left-handed junior college transfer from Snow College in Utah.

'I have no idea how Leach found Josh Heupel,' said Tulsa offensive coordinator Steve Spurrier Jr.

, son of legendary Florida coach Steve Spurrier and part of Stoops' first OU staff.

'But one of the really important variables for Leach when he recruited quarterbacks was, what kind of completion percentage did they have? He doesn't have to hit deep balls.

Doesn't have to have a really strong arm.

But he has to throw completions.

That was always crucial in his offense.

And that was always crucial in his evaluation of quarterbacks.

'Heupel didn't have the rocket arm coveted by NFL scouts or other blue-blood college programs.

He couldn't run much, either.

But Heupel could put the ball on the money.

And, as a coach's son, he knew where to go with it, too.

That first year, Heupel spent much of his free time with Leach mastering the Air Raid, an offensive scheme designed to spread the field and attack the defense with quick passes.

'Josh was a QB rat.

He wasn't into going out and partying.

He was a football junkie,' Gundy said.

'That was perfect for Mike Leach, because obviously Mike liked to stay up late at night.

' That first season, for a program best known for Barry Switzer's wishbone running attack, Heupel led all Power 5 quarterbacks with 310 completions, as Stoops' Sooners showed promise.

'We had the players.

We just had to get the right coaches, structure, discipline.

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and the right quarterback,' said Rocky Calmus, an All-America linebacker for the Sooners then.

'Josh would be the first to tell you he didn't have the strongest arm, but he was accurate.

He read it and he could put it where it needed to be.

'The Sooners were on the way up.

Yet almost no one considered them national championship contenders heading into 2000.

OU opened ranked 20th in the preseason polls.

The night before their first preseason practice, Heupel addressed the team and told them they needed to aim higher.

'I wish somebody had recorded it.

To this day, it's the best speech I've ever heard,' said White, a redshirt freshman that year.

'His whole point was, why not us? He kept saying it.

Why can't we win the Big 12? Why can't we win a national championship?' Gundy and Spurrier stood at the back of the room.

When Heupel uttered 'national championship,' they looked at each other in disbelief.

'We were not prepared for that.

But Josh Heupel was,' Gundy said.

'The belief that Josh Heupel had and what he portrayed while he was here got this whole team going.

The belief that we could be better than everybody, that we could win every game—that came from Josh Heupel.

'Flying under the radar, the Sooners roared through a three-game stretch that OU fans would term 'Red October.

' The Sooners annihilated No.

11 Texas 63-14, then knocked off second-ranked Kansas State 41-31.

That set up a showdown against top-ranked Nebraska.

The vaunted Huskers quickly jumped to a 14-0 lead.

'We couldn't have started off any worse,' said Torrance Marshall, OU's other star linebacker then alongside Calmus.

'But Josh didn't blink an eye.

He didn't let that moment be too big for him and had the leadership to bring us back.

' With two Huskers in his face, Heupel lofted a 34-yard touchdown pass on third-and-14 to Curtis Fagan in stride to tie the game.

The Sooners rolled the rest of the way to win 31-14 and claim the No.

1 ranking in the polls.

Like any other player, Heupel still had nerves.

Calmus remembered him either throwing up or dry heaving in the locker room prior to every game.

Calmus would wait for him to 'get it out,' as the two captains usually took the field last.

But Heupel's demeanor while on the field helped give those Sooners a unique resiliency.

'He was remarkably calm in who he was,' Spurrier said.

'A calm confidence about him that rubbed off on other people.

' The Sooners didn't always win easily.

But they remained calm in tight moments, especially in dramatic victories over Texas A&M, Oklahoma State and Kansas State again in the Big 12 championship game.

The undefeated Sooners advanced to the Orange Bowl to face Florida State for the national title.

The defending champion Seminoles, led by 28-year-old quarterback Chris Weinke, were double-digit favorites to repeat.

Before flying to Miami, the Sooners held a watch party at their team facility to see if Heupel won the Heisman Trophy.

Instead, Weinke narrowly edged out Heupel in one of the closest Heisman votes in history.

'I felt that Josh got robbed,' Marshall said.

'I was prepared to show [Weinke] why he shouldn't have gotten it.

' 'I told [Weinke], 'You got my boy's trophy,' and he said, 'No, I don't.

' I said, 'Yeah, you do—and we're going to find out today,'' Marshall recalled.

'And I meant it.

I was dead serious about it.

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We wanted to go out there and show them that we were the better team, we had the better quarterback, and you guys did make a mistake and didn't give the right person the Heisman.

'The OU defense forced Weinke into three turnovers, including a Marshall interception, and didn't allow the Seminoles offense to score.

Heupel and the Sooners did enough offensively to win 13-2, capping off a magical season.

'I remember thinking to myself then, that dude's going to be a great coach,' White said, 'just because of how he's handled me.

' In 2006, after a short stint at Arizona, Heupel returned to OU to be its quarterbacks coach.

That preseason, starting quarterback Rhett Bomar was dismissed from the team for accepting money from a local car dealership for work he didn't do.

On the fly, Heupel helped Paul Thompson adjust from receiver to playing quarterback again.

Thompson wound up throwing for 22 touchdowns, as OU won another Big 12 title