INDIANAPOLIS – They line up next to each other on punt coverage.

Edwin Jackson is the tackle. Antonio Morrison is the guard.

They communicate. Work together. And their cohesion has helped Pat McAfee to the league's third best net punting average.

Jackson and Morrison are going to be lining up next to each other again.

This role? It's not just a handful of snaps come fourth down, when McAfee's right leg largely dictates how much impact they have on a play.

This job could be more than 60 defensive snaps of a matchup being labeled as “Game Seven” by their teammates.

Come Sunday, the Colts starting inside linebackers are expected to be: a player who was signed to the team's practice squad a year ago Thursday, and a rookie making his first NFL start.

Bring it on, says Jackson.

"I feel like me and Antonio have a good relationship on and off the field," Jackson says of the man two lockers down from him.

"I feel like we have the camaraderie to accept this challenge. I'm confident going through this week."

Jackson talks like a confident man.

Being more vocal in the coming weeks, with the Colts without the suspended D'Qwell Jackson for the rest of the season, should not be a problem for Edwin.

Making up for the elder Jackson is a loss, particularly from what he did for the defense before the snap.

D'Qwell was the defensive signal caller since he joined the Colts in 2014.

It was his responsibility to take the defensive calls from Greg Manusky/Ted Monachino and make sure each level of the defense knew what was happening.

That reliability and trust is now gone.

It's coming to Edwin.

"We have to have great communication," Edwin says of him now handling the defensive signals. "(D'Qwell) takes authority when he's on the field and we have to emulate that when we get out there.

"This week I'm really going to focus even more in stepping up in that leadership role throughout practice and making sure that everything is kind of the same when he was here in the meeting rooms, making sure that everyone as that same focus throughout the week."

At various times on Monday against the Jets, Edwin did get some opportunities to make the calls.

The Colts used Edwin in one-man inside linebacker packages, therefore putting the pre-snap communication on him.

Then in the fourth quarter, with D'Qwell out of the game due to a concussion, the Colts had Edwin and Morrison working together.

"That was important because that was my first time actually getting the calls and relaying it to the guys," Edwin said on Wednesday. "As a defense, that's confidence that, 'Hey, we can trust this guy throughout the defense,' That's a big deal going into a week like this.'"

With Morrison the expected starter moving forward, the Colts are putting a player on the field who they feel has tremendous football IQ and understanding of this scheme, despite being a rookie.

The thought of using Clayton Geathers at linebacker is on hold for at least one more week. A neck injury has Geathers listed at "week-to-week."

That means Edwin Jackson and Antonio Morrison in the expected starting 11 for the biggest game of the season.

At Wednesday's practice, when the Colts began their special teams drills, Edwin drifted away with linebackers coach Jim Herrmann.

It was time for the one-on-one teaching that D'Qwell Jackson always had during that time of practice.

The interaction and teaching now is for Edwin.

Ask the new leading man in the middle of the Indy defense about what is coming at him this week---and Sunday 1:00 p.m. can't arrive soon enough.

"The jitters are out," a smiling Edwin Jackson says.

"It's go time now. We are trying to get into the playoffs."