Can the secondary keep up and cover receivers against a strong quarterback? The Dolphins’ defensive backs relinquished huge plays exactly when the Colts’ backs were against the wall. They were outleaped by former FIU star T.Y. Hilton.

It was a regression game for Sean Smith and Jimmy Wilson.

On three crucial third-down plays, Indianapolis converted and went on to score a field goal, a touchdown and the winning field goal.

“I don’t know if there’s anybody that hasn’t had a game where you come off and say, ‘How did that happen?’ ’’ said defensive coordinator Kevin Coyle. “Well, this is one of them, and I’ve got to be honest with you, I’m disappointed. I’ve never seen us get in a situation where we had a team in third-and-long and weren’t able to cash in.”

The Dolphins lead the league in pass attempts against them with an average of 44.5. It’s a high risk-reward scenario. They have to create more turnovers when they force the opponent to go airborne.

“It’s a combination of we’ve got to do a better job in coverage and we have to continue to do a good job in the rush and against the running game,” Coyle said. “I think when you make teams throw the ball as much as we are, usually good things are going to happen sooner or later.”

Can Ryan Tannehill avoid a second-half slump? No one expected Tannehill to be as good as Luck, but hardly anyone expected Tannehill to be as poised and accurate as he has been so far. He has thrown zero interceptions in his last 98 attempts. Against the Colts, he showed he can throw on the run with defenders in hot pursuit. He didn’t look like a rookie on his sideline completion to Brian Hartline.

“Ryan has light years to go but he has come a long way, too,” Sherman said. “I am really excited about where he’s going to end up because he is his own worst critic and very seldom does he make the same mistake twice.”

At the pivot point of the season, the Dolphins are in good hands with calm, thoughtful coach Joe Philbin and his staff. They could finish what was supposed to be a rebuilding year way ahead of schedule. After all, a dozen more points and Miami could be 7-1 instead of 4-4.

“My wife had to remind me of this [Sunday night] because I wasn’t feeling too good,” Coyle said. “It kind of dawned on me that, yeah, we’re making progress but we’re not where we want to be. I believe in these guys and we’re going to go out and take the second half of the season.”