Heck, all anyone had to do was watch the Colts' offense bog down on another ragged Sunday.
With the AFC South all but wrapped up following a 22-14 victory over Tennessee, Luck made it clear this is not how the Colts want to go into the playoffs — struggling to move the ball, struggling to get in the end zone.
"We know we can't survive our mistakes forever," Luck said. "We've still got a lot of mistakes to clean up. We've still got a lot of things we need to improve on, but to grind out games, to win these types of games are a positive sign."
Hey, at least it's progress.
Indy (8-4) came into Sunday with losses of 29 and 30 points in two of its last three games and having been outscored 93-12 in the first halves of the last four games.
On Sunday, thanks to some costly Tennessee miscues, the Colts matched that combined point total in just two quarters despite struggling to finish drives. That's where the focus will be starting Monday.
Yes, the Colts have a virtual lock on their first AFC South title of the post-Peyton Manning era. Sunday's win gives them a three-game lead with four to play and the tiebreaker, courtesy of a season sweep over the Titans. Indy can clinch its eighth division crown in 11 seasons with one more win, one more Titans loss or a tie by either team.
That's not how the Colts are approaching it.
"We're not exhaling. We've still got, the division is not sewn up," coach Chuck Pagano said. "We've still got a lot of work to do as a football team in all three phases. We're not exhaling. We're going to do everything within our power to keep trending in the right direction."
Here are five things we learned from Sunday's game.
MISTAKES HURT: Tennessee (5-7) tried desperately to get itself back in the division chase. But Ryan Fitzpatrick threw three interceptions and lost a fumble that thwarted a possible score and turned into the Colts go-ahead field goal. The worst mistake may have come late in the first half when it appeared time had run out on the Colts after a Fitzpatrick interception. Instead, Moise Fokou was called for a personal foul, the officials added 1 second to the clock and Adam Vinatieri made a 37-yard field goal to give Indy a 12-7 lead.
BROWN DELIVERS: Pagano went with Donald Brown instead of Trent Richardson at running back and the Colts' 2009 first-round draft pick made it pay off. Despite running for 8 yards in the first 52 minutes, he ran for 46 yards on Indy's game-sealing drive and scored the Colts only TD of the day with 1:56 left. With 14 carries for 54 yards, he's likely to get another start next week.
TIGHTENING UP: Tennessee won't spend this week just trying to fix problems, the Titans need to start getting healthy. Tennessee started the day without tight end Craig Stevens (concussion) and lost two more tight ends during the game — Delanie Walker (concussion) and Collin Mooney (leg). Coach Mike Munchak did not provide a postgame update on either injury. The short-handed Titans then started using offensive tackle Mike Otto as a blocking tight end. But they need more than just a plug-in to make a playoff push.
DEFENSIVE UPRISING: The Colts' defense finally reverted to its early season form Sunday. They forced Fitzpatrick into mistakes, held up against the run and limited the points. If they can continue to play this way, Pagano knows he will have one part of his team ready for the playoffs.
THE TEST: Indy is about to find out just how good it really is. It has played well against some of the league's best teams — beating Denver, San Francisco and Seattle — among others. Next week, they head to Cincinnati and two weeks after that they go to Kansas City. Those games should give them an idea of where they stand heading into the playoffs.