"We know we have to play a lot better," O'Brien told reporters after the game.
Houston prevailed despite gaining only 229 yards and turning the ball over twice.
The Texans won 11 games and the division in 2018, and their path back to the playoffs became a lot easier in August with Andrew Luck's sudden retirement. Anything less than a successful defense of their division crown would've been a disappointment.
This year is pivotal for O'Brien.
O'Brien received offseason criticism as Houston received a marginal return—Jacob Martin, Barkevious Mingo and a 2020 third-round pick—for Jadeveon Clowney and paid a steep price for Kenny Stills and Laremy Tunsil. The Miami Dolphins received two first-round picks and a 2021 second-rounder as part of the deal.
O'Brien also acquired Duke Johnson, Carlos Hyde and Gareon Conley in a series of additional trades.
Bleacher Report's Mike Tanier argued Dec. 3 the team's performance was vindicating O'Brien:
"O'Brien's wheeling and dealing reshaped the team's roster and identity, particularly on offense.
"Stronger opponents can no longer just double-team [DeAndre] Hopkins while chasing [Deshaun] Watson all over the field the way the Colts did in last year's playoffs. Stills and Will Fuller V provide deep threats for Watson, Johnson offers a safety valve, and Hyde gives the team a chance to enjoy more 2nd-and-5 opportunities instead of constantly playing behind the sticks. Tunsil commits his share of penalties but allows few pressures, giving Watson time to stand in the pocket and find all those non-Hopkins people."
Watson is having a standout year, entering Week 16 with 3,668 yards, 26 touchdowns and 11 interceptions in 14 games.
Hyde and Johnson are providing a dimension Houston's offense lacked a season ago. Entering Saturday, Hyde had run for 1,030 yards and five touchdowns as the team's primary ball-carrier, with Johnson logging 394 yards and one touchdown on just 77 carries.
The Texans have slipped from seventh to 27th in defensive efficiency, per Football Outsiders, which raises obvious concerns. The decline isn't surprising after the team not only traded Clowney in September but also lost J.J. Watt to a season-ending torn pectoral in October.
The Texans earned a season-defining 28-22 win over the New England Patriots in Week 13 but gave up 448 yards in the process. They also allowed 491 yards in a 41-7 loss to the Baltimore Ravens in Week 11.
Those two teams could stand between Houston and Super Bowl LIV, and they both basically moved the ball at will on the Texans.
An elite defense is no longer a requirement to win a Super Bowl, but the 2018 Kansas City Chiefs showed how a below-average defense can be a fatal flaw.
With the postseason a guarantee, O'Brien and his staff can look ahead a little bit to try to figure out how to work around the Texans' defensive issues.