Both the Colts and the Texans have strong enough teams where they can make the playoff. Whichever team doesn’t win the division is still a strong candidate for a wild card. But winning the division is the only sure way to make sure you get a playoff berth.
That is what’s largely on the line tonight: the division title. If the Colts win tonight, they essentially take a two game division lead with five games to play. That would make it tough for Houston to overcome. It would also put the Colts in the number three seed slot right now.