DETROIT >> There was a time when, organizationally, the Tigers feared Kerry Carpenter might be a defensive liability in the outfield. There was a time when they discussed the pros and cons of grooming a mid-20s player to be a designated hitter.

That all seems unfathomable now. Through his own relentless work and unflagging self-belief, Carpenter has grown into, not just a serviceable defensive outfielder, but an impactful one.

“He has been the most outspoken about wanting to be an outfielder,” manager AJ Hinch said. “And not wanting to be a mid-20s DH and not wanting to be known just for his bat. He wants to contribute on both sides of the ball.

“And by his play, he’s really forced me to keep him in the outfield and DH Mark (Canha) or Riley (Greene), because I like the look. I like his actions in the outfield now more than ever.”

Carpenter’s main tool is his power bat and that has been red-hot of late. He hit his seventh home run of the season Friday night. He’s collected six extra-base hits in his last eight and ranks seventh in the American League with a .553 slugging percentage.

But he changed the course of Friday’s game with his defense, specifically, with his arm. He erased a run in the first inning throwing out Vladimir Guerrero Jr., at the plate with a 90-mph strike to catcher Carson Kelly.

“I’ve been confident in my arm for years now,” Carpenter said. “It was pretty cool to see it get some results.”

It was his second outfield assist this season and 10th in his three seasons in the big leagues. Sports Info Solutions grades him as a plus-3 in defensive runs saved.

His calling card is his bat; the defense is a point of pride.

“I enjoy being out in the field every day these days,” Carpenter said. “It’s been my goal. At the beginning of the year it was kind of tough, just DHing most days and then trying to go out there and get into a rhythm. I’ve been out there most days now and I’m in a good rhythm.

“The more I play out there, the better I get out there and the better I get the more confident I get.”

Carpenter’s reads off the bat, the routes he takes to the ball, the aggressive way he attacks base hits and his ability to cut balls off in the gap have all been markedly improved over his three seasons.

But the arm strength has been a revelation. Accuracy was never a problem, but he wasn’t throwing 90-mph missiles to home plate three years ago.

“Just, like, the lifts that I do and all the throwing drills, trying to long toss as much as possible, it’s a mixture of all of that,” he said. “It’s something that’s continually gotten better through the years. My arm is strong.”

His outfield development started with Arnie Beyeler. Beyeler, now the Tigers organizational outfield and baserunning instructor, was Carpenter’s manager at Double-A Erie.

Once he got to the Tigers, George Lombard and Gary Jones have been molding him and refining his mechanics and footwork.

“The two areas Kerry has grown the most are his reads off the bat and his fearlessness,” Hinch said. “And what comes with that is the arm strength and the conviction to throw the ball. He throws the ball the lowest, height-wise, meaning he’s going to throw through the cutoff man and make a fundamentally-sound throw.

“He puts himself in a good position to make a really good throw.”

The next step in Carpenter’s quest to be the Tigers’ everyday right-fielder will be his at-bats against left-handed pitching. He’s caught in the dreaded Catch-22 right now — he needs opportunity to get better at it but he needs to be better at it to earn the reps.

He’s 1 for 16 in just 18 plate appearances against lefties entering play Saturday, .206 with a .575 OPS in 120 plate appearances over his career.

Miller itching to pitch

Right-handed reliever Shelby Miller is on track to make a rehab outing with Toledo as early as Tuesday.

He’s been out with irritation in the ulnar nerve in his right elbow and had a hydro-dissection procedure to break up some scar tissue. He’s thrown two bullpen sessions and is scheduled to throw another Sunday.

“We strengthened up the area a little bit, got some strength around my nerve” Miller said. “And breaking up the scar tissue helped a little bit. Can’t really say what helped and what didn’t but it’s feeling a lot better, not nearly as stiff as it was.”

Miller said the nerve didn’t bother him, pain-wise, while he pitched, though he was confounded by a 2-3 mph dip in his velocity.

“It was more like, ‘I don’t throw 91,’” he said. “Something was off.”

The soreness, though, was the real problem. It was more intense than usual after his outings and it was taking him a longer time to recover.

“Just chalk it up to getting myself better,” he said. “It’s still early in the season. There was no reason to push it and damage something else further.”

Hinch said there were still some boxes to check before Miller started his rehab assignment.

“I hope to meet with Shelby today and the rest of the medical staff and get the final sign-off,” he said. “But the rehab outing is the natural next step in the progression. The exact timing, how many (outings), what he’s going to do — we need to have a few more conversations before we know.

“The good news is, he’s itching to pitch. Which to me means he’s cleared all the hurdles of his worrying about how his arm is feeling.”

Around the horn

Mark your calendar. The Tigers have changed the start time for the game Sunday, Sept. 15 against Baltimore to 12:10 p.m. That is in response to traffic concerns with the Lions hosting Tampa at 1 p.m. at Ford Field the same day.