Doyel: We know nothing about the Colts

• Preseason finale: Bengals at Colts, 7 p.m. Thursday, Fox

ST. LOUIS – Here’s what we know about the Indianapolis Colts, three games into the preseason:

We don’t know anything about the Colts.

The offensive line is lousy, except when it’s not. And Saturday night in a 24-14 victory over the St. Louis Rams, it was not lousy. Mostly. Except for that time when Jonotthan Harrison played, which we’ll get to in a minute.

Receiver Duron Carter and cornerback Jalil Brown are disappointing, except when they’re not. And Saturday night against the Rams, they were not disappointing. Mostly. Except for that one play by Carter, which we’ll get to in a minute.

Running back Josh Robinson is the goods, except when he’s not. And Saturday night against the Rams, he was not the goods. Except for that one play, when he saved Andrew Luck a trip to the emergency room. Which we’ll get to in a minute.

VICK BALLARD: Is time running out on the running back?

The starting secondary is the defense’s strength, except when it’s not. And Saturday night, it was not. Mostly. OK, entirely. The starting secondary was not good, allowing Rams quarterback Nick Foles to complete 10 of 11 passes for 128 yards, a touchdown and a 145.5 passer rating. Foles was pretty much throwing a perfect game when he was removed at halftime. And so that’s enough written about the secondary – nothing worth getting to in a minute here – other than this sentence that we’ll get to right now:

The Colts seemed to miss cornerback Greg Toler. Is this not making any sense? Good. You’re paying attention.

Me, I was paying attention to Duron Carter and Josh Robinson and Lance Louis and the Pro Bowl defensive back duo of Vontae Davis and Mike Adams – whose miscommunication on a zone coverage led to an easy 44-yard touchdown pass from Foles to Chris Givens – and I was not recognizing what I was seeing. Because it wasn’t what any of us had been seeing through two preseason games.

Did you see the play Carter made during the Colts’ field-goal drive late in the first half? The stat sheet will show it was a 14-yard catch, nothing much really, but the eyes showed something else. They showed Luck being hurried by one of the werewolves on the Rams’ defensive front and unloading the pass a fraction of a second ahead of schedule, well before Carter made his cut on a down-and-out pattern. By the time Carter turned and looked for the ball, it was almost on top of him. He had time only to throw his hands up in self defense, and the ball stuck like a fly on glue.

That was a special play, the kind of play Carter was making every day in camp at Anderson and never, not once, in the first two preseason games. Carter, the first receiver beyond the established triumvirate of T.Y. Hilton, Andre Johnson and Donte Moncrief to get a snap Saturday night – rookie Phillip Dorsett (knee) was held out for precautionary reasons – added two more catches.

On the down side, Carter allowed himself to be redirected inside on a lob to the outside on third-and-goal from the 3. Luck threw a designed jump ball for the 6-5 Carter, but he wasn’t in the vicinity after being shoved inside by 6-0 Rams cornerback Marcus Roberson.

COLTS OFFENSE: A night of almosts

All in all, though, it was major progress for a camp revelation and preseason-game disappointment. Carter, I mean. Though the same could be said of Jalil Brown, the cornerback who drew raves in Anderson and hadn’t been heard from since – until Saturday, when he picked off Sean Mannion in the third quarter.

Not to be all juvenile and declare this game something silly like Opposite Day, but, um. Well.

This game was Opposite Day.

The offensive line, much maligned all preseason by everybody who has been paying attention, more than held its own against a Rams defensive front that could be among the best in the NFL.

“They did a great job,” Luck said of the line.

“Proud of our offensive line,” coach Chuck Pagano said.

“Got better,” right tackle Jack Mewhort said. “Got to keep trending in that direction.”

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The line was fine, until the Colts inserted Harrison at center over starter Khaled Holmes in the second quarter. With the Colts pinned back to their own 6, Harrison and guard Todd Herremans were demolished on consecutive plays – nearly leading to a safety. Holmes replaced Harrison on the next series, and the line was back in business.

The line was good, that is, except for the times Josh Robinson carried the ball. In the first two preseason games Robinson was making defenders miss, but in this game he was making like Trent Richardson – five carries, four yards – and also losing a fumble at the Colts’ 14 on the first play of the third quarter. Luck took the blame for the fumble, because that’s what Luck does, but it was Robinson who dropped it, then dived into the pile for it and left with a concussion. Bad day all around for one of the team’s top performers through two games.

The contest at backup running back between Robinson and Boom Herron (nine carries, 25 yards)? No contest, though Robinson did have one highlight: He demolished oncoming Rams defensive end Eugene Sims, giving Luck the time to find Andre Johnson for a 32-yard touchdown in the first quarter.

Backup quarterback Matt Hasselbeck, so bad for the first two preseason games, was so good on Saturday (10 for 14, 62 yards).

Punt coverage, so leaky for two games, was tight on Saturday (two returns for five yards, total, for the Rams).

Luck, so good most of the time, threw a bad interception (nullified by a Rams penalty) and missed T.Y. Hilton on a possible touchdown.

“Just a bad throw,” Luck said

So many things, not adding up.

Except for this: Pat McAfee averaged 51 yards on five punts and converted an on-sides kick. Adam Vinatieri was perfect on four kicks, including a 55-yard field goal.

Injury-stricken running back Vick Ballard, bless his heart, missed this game with a pulled hamstring. Injury-stricken defensive tackle Art Jones, last year’s big-money offseason acquisition who was derailed by an injury to an ankle, left Saturday’s game with an injury to an ankle. And outside linebacker Bjoern Werner, a disappointment since being picked in the first round of the 2013 draft, was a disappointment Saturday night.

Some things, they just don’t change.

Find Star columnist Gregg Doyel on Twitter at@GreggDoyelStar or atwww.facebook.com/gregg.doyel