McNair arranged to fly Watson and Watkins to Washington to allow the duo to celebrate the Tigers' national championship with President Donald Trump, NFL Network Insider Ian Rapoport reported.
Watson, who was selected by Houston with the 12th overall pick of the 2017 draft, delivered the go-ahead score with one second remaining on a 2-yard touchdown pass to Hunter Renfrow, sealing a 35-31 win over Alabama in January.
The quarterback was named the game's MVP after completing 36 of 56 passes for 420 yards and three touchdowns while adding 43 yards and another score on the ground.
Watkins, a defensive tackle, was taken in the fourth round by the Texans. Listed at 6-foot-3, 309 pounds, Watkins had 10.5 sacks last season for the Tigers.