Georgia
Head coach Kirby Smart and the Georgia Bulldogs are the only team that has defeated Sarkisian and the Longhorns this season. Georgia topped Texas in mid-October at DKR by two scores during the regular season.
Texas came up short against Georgia in overtime at the SEC Championship Game in Atlanta in early December.
If Texas does make it to the College Football Playoff National Championship Game, the three most likely opponents for the Longhorns would be Penn State, Georgia, or the Notre Dame Fighting Irish. I would assume it would probably be the winner of Notre Dame-Georgia that makes the national championship game from the other side of the Playoff bracket.
Georgia faces massive uncertainty on the offensive side of the ball this postseason due to a season-ending upper-body injury to starting quarterback Carson Beck. Backup quarterback Gunner Stockton led the Dawgs to an overtime comeback win over the Longhorns in the SEC Championship Game.
But Stockton hasn't started a single game in his collegiate career, and he's about to face one of the nation's toughest defenses in the Playoff quarters against Notre Dame's defensive front seven.
We've already seen the problems for the Longhorns that a matchup against Georgia presents in the trenches against the Dawgs' stout and athletic defensive front. I hesitate to think that any team presents a tougher matchup on the surface for this postseason at any point than Georgia for Texas in the Playoff.