A quarter-century ago, Josh Heupel was one of the centerpieces of Oklahoma’s football rebirth.On Saturday, Heupel will be a piece of another significant milestone when his sixth-ranked Tennessee Volunteers take on the No. 15 Sooners in Norman, Okla.Oklahoma will be playing its first league contest since joining the Southeastern Conference.”It will be unique going back into that stadium,” Heupel said. “I have teammates and friends back there. It’s going to be a (different) viewpoint. I am not sure I spent a day on the opposing sideline inside the stadium — not even for a scrimmage.”Heupel signed with the Sooners out of Snow College in Utah, not long after Bob Stoops’ arrival as Oklahoma’s head coach before the 1999 season.The Sooners made their first bowl game in five seasons during Heupel’s first season. During his second, Oklahoma went undefeated and won the program’s seventh national championship. Heupel also finished runner-up in the Heisman Trophy voting that season.Brent Venables, now in his third season as the Sooners’ head coach, was Oklahoma’s co-defensive coordinator during Heupel’s time as a player.Heupel was also a longtime assistant at Oklahoma under Stoops but was fired following the 2014 season. After stints at Utah State and Missouri, Heupel got his first head-coaching job at UCF, and he is in his fourth season as the Volunteers’ head coach.Venables expects a strong reception for Heupel in Norman.”There can’t be someone with a stronger legacy,” Venables said. “The first year, going 7-5, then out of nowhere to go 13-0 and several games within that year, Oklahoma was an underdog or had to come from behind in those games where you really felt Sooner Magic was reignited. And he was a catalyst of that. And people won’t forget that.”The game is about much more than Heupel’s return or the Sooners’ introduction into the SEC.Tennessee (3-0) comes in with one of the most powerful offenses in college football, having outscored its opponents 191-13.