Dallas Renegades quarterback Landry Jones left Sunday's 27-20 loss to the Houston Roughnecks with a left knee injury in the fourth quarter.
Jones suffered the injury on a successful fourth-and-1 conversion on a quarterback sneak.
Dallas coach Bob Stoops said after the game that he doesn't know the severity of Jones' knee injury and that the quarterback will have an MRI, which will likely happen on Monday.
The injury was noted on Twitter by Kansas City Chiefs quarterback Patrick Mahomes, who suffered his own knee injury last season on a quarterback sneak.
Hope @LandryJones12 is all good!
— Patrick Mahomes II (@PatrickMahomes) March 1, 2020
Jones, who played for five seasons as a backup with the Pittsburgh Steelers, was the first quarterback to sign with the XFL when he did so in August of last year.
Jones committed four turnovers before he was injured, throwing three interceptions and losing a fumble that was returned for a touchdown.
Philip Nelson replaced Jones and moved Dallas to Houston's 3-yard line but was intercepted after a pass was bobbled and caught by a Houston defender. The Roughnecks went on to run out the clock and improve to 4-0.
Dallas fell to 2-2 with the loss.