The Texans added Mills to their injury report and list him as questionable for Monday's wild-card game against the Steelers due to a personal matter.
According to Jonathan M. Alexander of the Houston Chronicle, Mills wasn't part of the Texans' traveling party to Pittsburgh, but the quarterback is set to board a commercial flight and is expected to join the team in advance of its postseason opener. In the event Mills runs into travel issues that prevent him from being available Monday, the Texans would still have Graham Mertz as a third quarterback on the roster to step in as the top backup to starter C.J. Stroud.