INDIANAPOLIS — The first step into a season of sudden promise without the quarterback of the future — let’s call it post-Anthony Richardson — was unsightly.

With Richardson’s availability for the remainder of the season very much in doubt, it’s fair to wonder if the coming weeks with Gardner Minshew II will offer any sort of promise.

Sunday did not.

Normally judicious with the football — 15 interceptions in 37 career games — Minshew littered EverBank Stadium Sunday afternoon with four turnovers that directly led to 17 Jacksonville points; a fumble on a sack and a career-high three interceptions that could have been at least five if Jaguars’ DBs had held onto the ball.

You can do the math.

Jaguars 37, Indianapolis Colts 20.

“Personally, I was not good enough,’’ Minshew said in his postgame press conference.

Colts coach Shane Steichen admitted it’s tough whenever a team turns the ball over four times — “17 points off turnovers,’’ he mentioned — but attempted to deflect the blame.

“Obviously it starts with myself,’’ he said. “I’ve got to be better for him in those situations.’’

Nice try.

This one was on Minshew, who was making his second start for the Colts and 26^th on his career. He was aided by a defense that did some good things — rookie JuJu Brents’ first career interception and sacks from DeForest Buckner, Samson Ebukam and Tyquan Lewis come to mind — but seemed to suffer communication breakdowns in the secondary that allowed too-easy Trevor Lawrence touchdown passes to Christian Kirk (29 yards) and Brenton Strange (10 yards).

The quarterback can’t be careless with the football and expect his team to win against the heavy favorite to win the AFC South. The Jaguars (4-2) gained sole possession of the division, and the Colts slipped to 3-3 as they saw their road losing streak to Jacksonville reach nine straight. That ties a franchise record against one team (Pittsburgh).

Minshew’s mistake-strewn afternoon might have been a one-off in his return to the franchise that selected him in the sixth round of the 2019 draft. He hadn’t suffered a turnover in his first five appearances, including as the starter in the Colts’ 22-19 overtime upset at Baltimore in week 3.

Four is too many just for about any team. Since 1984, the Colts are 5-54 when they have at least four turnovers and now have dropped 18 of their last 20 in that scenario.

In the two losses to Jacksonville in six weeks, the Colts have suffered seven of their eight turnovers, and the three in the opener were with Richardson under center.

The Colts hope Sunday was a temporary speed bump with Minshew under center, but it’s entirely possible they follow his lead the remainder of the season.

Richardson was placed on the injured reserve list last week with a grade 3 sprain to the AC joint in his right (throwing) shoulder. That requires missing at least four games.

However, on Friday Steichen did not rule out his prized rookie QB needing season-ending shoulder surgery.

“Obviously, we want to do the best thing for him,’’ he said. “Still relying on the doctors, and we’ll make that decision in a little bit.’’

Richardson was at practice all week with his right arm in a sling. He was on the sideline Sunday and had discarded the sling, but kept his right arm tucked against his chest.

Amanda Renner, CBS’ sideline reporter, approached Richardson Sunday and asked for an update on his status.

“Not quite sure yet what I’m going to do,’’ he told her.

NFL Network, citing unnamed sources, reported prior the game that Richardson is “strongly’’ considering shoulder surgery because it represents the best option to allowing his right shoulder to properly heal.

It was reported the Colts and Richardson have sought multiple medical opinions on Richardson’s shoulder. The MRI reportedly revealed the labrum in Richardson’s shoulder wasn’t torn and the ligaments “looked better than expected.’’

Everyone should brace themselves for Richardson being done for the season. A decision could be made in the new few weeks, perhaps sooner.

For now, the Colts’ fortunes are in Minshew’s hands. He set career-highs with the three interceptions, 33 completions and 55 attempts while finishing with 329 yards.

Minshew credited the Jaguars for exerting pressure all day (three sacks, six other QB hits, three tackles for loss) and limiting the success of the Colts’ run game by sticking with their base defense much of the day. Jonathan Taylor and Zack Moss combined for 40 yards on 15 attempts.

But he accepted much of the blame.

“At the end of the day,’’ Minshew said, “I was careless with the football. I didn’t do a good enough job taking care of it. I put our team in a really bad spot, you know, and that it’s not fair to the rest of the guys.

“So, I’m really going to look at those, hold myself accountable.’’

Things started about as well as could have been expected.

The Colts won the toss, took the football and Minshew led a Minshew-esque drive: 16 plays, 65 yards, 8 minutes, 33 seconds. Minshew completed his first nine passes to six different receivers, but two incompletions inside the 10 forced Steichen to call on Matt Gay for a 28-yard field goal and a 3-0 lead.

Things quickly got away from the Colts and Minshew.

After Jacksonville answered with an opening 13-play, 75-yard touchdown drive capped by a 2-yard run from tailback Travis Etienne, linebacker Josh Allen whipped Colts’ left tackle Bernhard Raimann for a sack/strip/lost fumble of Minshew at the Indy 22.

On the Jaguars’ first play after the Indy turnover, Etienne took a direct snap out of the wildcat around the right side for a 22-yard TD.

Two TDs in 16 seconds.

From down 7-3 to down 14-3.

And that was before Minshew had uncorked any of his interceptions.

The Colts were hanging around late in the second quarter despite getting little from their run game and being unable to push the football down the field in the pass game. They had a second-and-10 at the Jacksonville 30 with just under 5 minutes remaining.

That’s when Minshew “sailed” one over Michael Pittman Jr.’s head — his description — and the Jaguars cashed in with Lawrence’s 29-yard TD to Kirk.

Jacksonville had a firm grip at 21-6 at the half after Gay knocked down a 56-yard field goal with 6 seconds remaining.

Minshew overthrew Pittman again early in the third quarter, and the Jaguars capitalized with a Brandon McManus’ 48-yard field goal.

The Colts crawled out of a 31-6 hole to within 31-20 with Minshew’s 2-yard TD flip to rookie Josh Downs and halfback Zack Moss’ 3-yard run in the fourth quarter, but it was too little, too late. In between the two late TDs, Minshew suffered his third interception on a fourth-down throw to Pittman in the end zone.

“We’re not going to tuck our tail,’’ he said. “We’re not going to drop our chin. We’re just going to keep pushing through it, learn from it and we’ll come out the other side better.’’

The other side is the remainder of the season. Eleven games remain, and there are a slew of winnable games. That begins with upcoming home encounters with 3-2 Cleveland, which stunned San Francisco Sunday, and New Orleans, 3-3 after losing at Houston.

It’s likely Minshew’s show from here on out.

You can follow Mike Chappell on Twitter/X at @mchappell51.