ATLANTA — A pair of veteran-heavy teams in No. 1 Auburn and No. 2 Michigan State have a common denominator ahead of Sunday’s matchup in the NCAA Tournament South Region final — a pair of red-hot freshmen.With both the Spartans and Tigers’ seasons hanging in the balance Friday night, Michigan State’s Jase Richardson and Auburn’s Tahaad Pettiford helped guide their teams to Sweet 16 victories over Ole Miss and Michigan, respectively.Now with a ticket to San Antonio on the line, they’ll square off on the biggest stage of their young careers.Auburn (31-5) trailed the Wolverines by nine with just over 12 minutes remaining on Friday. But Pettiford scored 15 of his 20 points down the stretch, while Johni Broome (22 points, 16 rebounds) and Denver Jones (20 points) added enough firepower to help the Tigers pull away from pesky Michigan.Auburn coach Bruce Pearl — in search of his second Final Four (2019) — hopes to see the winningest season in program history prolonged, with the help of his savvy 19-year-old star.”I don’t think I’ve ever had a player that has been as good as Tahaad that only started one game,” Pearl said. “I just think that Tahaad feels prepared. He’s got a great stroke, and he’s always played against older players.”That’s one thing his dad did when he was growing up, is he always played him up even though he was small. He’s been playing guys older than him his whole life. So, what’s the difference in the NCAA Tournament?”Pettiford is averaging 19.7 points in Auburn’s three tournament wins, while Broome has added 14.7 points and 13 rebounds per game.Tasked with a matchup against Hall of Fame coach Tom Izzo, Pearl and the Tigers understand the challenge of facing off against one of the sport’s best.”They’ve always been as athletic as anybody in the backcourt,” Pearl said of the Spartans. “Michigan State has elite athletes in the backcourt. Like my athletes, they guard. They can score in multiple ways. … I’m obviously challenging my guards and challenging our athletes, but I think from that standpoint it’s an interesting matchup. Michigan won the Big Ten tournament. But Michigan State won the Big Ten. They are the best team in that league.”