INDIANAPOLIS — The Colts are not saying which quarterback they will start against the Seahawks.

Not yet.

Indianapolis is choosing between a 44-year-old Philip Rivers returning to the NFL after five seasons or rookie Riley Leonard, a sixth-round pick who is dealing with a right knee injury, although Leonard was able to practice throughout the week.

The Colts called Rivers on Sunday night, gauging his interest in coming out of retirement to help a team that lost starting quarterback Daniel Jones to a torn Achilles last week and was already missing backup Anthony Richardson because of a fractured orbital bone suffered in October.

“We’re going to have those conversations,” Indianapolis coach Shane Steichen said. “How he feels, how we feel about it here in the next couple of hours, and we’ll go from there.”

Rivers has spent the week of practice trying to figure out how his body will hold up to the rigors of playing NFL football again. He hasn’t played since the Colts’ 27-24 loss in Buffalo on Jan. 9, 2021; Rivers has been coaching high school football at St. Michael Catholic in Fairhope, Alabama.

“We’re going to find out that,” Rivers said in his interview Wednesday. “I know it is tough, and I know five years is a long time. Believe me, that weighed on me a lot. … It is a physical game, and it’s fast. And dudes are big and fast, just like they were, so I’m just … Shoot, taking it a day at a time, and I do feel good. There’s something about being back in this building that feels right.”

Rivers was a full participant in practice all three days, taking the first snaps in every quarterback drill during the portion of practice open to the media, although Steichen said Friday that Leonard had also been given snaps with the first-team offense.

From the sounds of it, Rivers jumped right back into the huddle like he’d never left.

Fourteen of the players on the roster were here in Indianapolis in 2020, including a handful on offense: running back Jonathan Taylor, wide receiver Michael Pittman Jr., left guard Quenton Nelson, tight end Mo Alie-Cox.

“He’s got great command in the huddle, he was throwing it well,” Steichen said. “We’re excited for it. He’s fired up for it, for the challenge. Obviously, getting back into it, getting back into the fold, feeling the pass rush, got some good work in that. Moving around, seeing the defense, it was good.”

Rivers also has a longstanding relationship with Steichen, going back to their days together with the Chargers. The two men talk regularly, trading notes on what’s going on with the Chargers and what’s going on at St. Michael Catholic.

“He picked up where he left off five years ago,” Steichen said. “Seeing the game, seeing different looks. …  It was back and forth, ping-ponging, ping-ponging ideas off each other in the quarterback meeting room, talking to the wide receivers and how he sees things.”

Rivers knows the physical rigors of the game can’t be simulated in practice.

Quarterbacks don’t get hit in practice, and an NFL practice session can’t perfectly simulate the intensity of an NFL game.

“You try to do it in practice as best you can,” Steichen said. “Obviously, the game’s a little different. The game speed’ll be a little different for him, so that’ll be an acclimation period for him if he’s out there.”

What the Colts have seen from Rivers this week, though, has impressed the team, beginning with his throwing workout on Monday, and all the way through practice.

“I’ll say, it was pretty good,” Steichen said. “A guy that hasn’t been out there in five years, to go out and practice the way he did was pretty impressive to watch.”

Indianapolis plans to spend the rest of Friday deciding if the rest of the country will get to watch Rivers back on the field on Sunday in Seattle.

When is Philip Rivers’ first game?

Rivers’ first for the Colts could be against the Seattle Seahawks on Sunday.

Is Philip Rivers a grandfather?

Yes. Rivers’ oldest child, Halle, 23, has a one-year-old son.

How many children does Philip Rivers have?

10; ranging in ages from 1 to 23. Halle, Caroline, Grace, Gunner, Sarah, Peter, Rebecca, Clare, Anna and Andrew.

How old is Philip Rivers?

He turned 44 on Monday.