JACKSONVILLE, Fla. -- Three failed fourth-down attempts did the Indianapolis Colts in against the Jacksonville Jaguars on Sunday, and it might end up costing them a playoff spot.

The Colts' five-game winning streak ended after coach Frank Reich put too much faith in his offense against one of the best defenses in the NFL. The Colts (6-6) were turned away on all three fourth-down tries in their 6-0 loss to the Jaguars.

"We started slow, finished slow and we never caught our rhythm," Colts tight end Eric Ebron said. "We never caught a break. We had plays and it got brought back. We didn't have any breaks."

Sunday was the first time Colts quarterback Andrew Luck was shut out in his career, and it came at a horrendous time for the team.

The Colts have gone from feeling like they controlled their own destiny in their push to make the playoffs for the first time since 2014 to now having that destiny out of their hands.

They're a long shot to win the AFC South, especially after Houston (9-3) easily beat Cleveland to increase its lead to three games over the Colts in the division. Baltimore (7-5), which already owned the tiebreaker over the Colts, widened its lead with a win in Atlanta. Denver (6-6), Miami (6-6) and possibly Tennessee (5-6) muddle up the playoff race, too.

"11-5 gets you in. 10-6 gets you in, but 9-7 does not get you in," Colts receiver T.Y. Hilton said. "We can't lose anymore. Have to go out there and play."

The Colts believe they should have had another play after the clock wasn't stopped at the end of the game, but their issues Sunday went beyond that final play.

Their issues were on fourth down.

Reich's coaching style is that he won't adapt to the opponent's defense; the defense will have to adapt to the Colts. That's why it wasn't surprising that Reich, not worried that he was facing the NFL's fifth-ranked defense, gambled three times.

Reich's decision to go for it was questionable because points were going to be hard to come by. You can understand the Colts being more aggressive if they were playing the likes of New Orleans, the Rams or Kansas City where field goals wouldn't do any good against those high-scoring offenses. But the Colts were facing a Jaguars team that benched its starting quarterback, fired its offensive coordinator and didn't have starting running back Leonard Fournette (suspended).

If Jacksonville was going to win, it was going to be because of its defense. And that's exactly what happened.

The first failed attempt -- a shovel pass to running back Jordan Wilkins -- came up a yard short of the goal line. It came after a penalty on an Adam Vinatieri field goal gave the Colts a new set of downs.

"It's a pretty strong go, especially with our defense playing the way they were playing. We had a play that we really liked that had multiple options on it," Reich said. "If it's man-to-man, it goes to T.Y. probably. If we don't get it and had them backed up and our defense goes three-and-out, we'd get it back in field goal position. That's why all the numbers say 'strong go' there. The call was a call we practice a lot and we like that call."

The Colts left three more points on the board when they needed a yard on fourth down with the ball at Jacksonville's 31. The Jaguars sniffed out the handoff to tight end Ebron, causing him to fumble behind the line of scrimmage.

The Colts' final failed fourth-down attempt came a possession earlier from Jacksonville's 19-yard line with less than three minutes left. Needing only a yard, they lined up in a power formation with tight end Ryan Hewitt as the fullback. The Colts' attempt to pick up the yard through the air never developed because Jaguars safety Ronnie Harrison went in untouched to sack Luck.

"They were making the plays consistently, and we weren't," Luck said. "We had our opportunities and we didn't execute. Credit to them, they played better than us ... It felt like it was an uphill climb with some self-inflicted wounds."

The Jaguars held the Colts to 265 yards of total offense, and Indianapolis came away empty-handed on five attempts inside Jacksonville's territory.

"We knew coming in they were going to throw the book at us, but at the end of the day we wanted to jump out on them early and they were going to lay down," Hilton said. "That's what happens when you let teams hang around. It goes the other way every time."