Detroit Tigers left-hander Tarik Skubal looked like himself in his long-awaited return from flexor tendon surgery.

Only better.

His fastball was faster. His slider shape had more depth. His refined mindset gave him the confidence to fill up the strike zone relentlessly. The Oakland Athletics, the worst team and the worst offense in baseball, couldn't touch his nasty five-pitch arsenal, going hitless through four innings.

The 26-year-old improved as a pitcher while rehabbing.

"I kind of expect Skubal to be a monster every time," Tigers manager A.J. Hinch said after Tuesday's 1-0 loss in extra innings. "The best part was how much he harnessed his emotions. ... But I expect him to be great. He's one of the best pitchers in baseball, quite honestly, when he's right."

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Skubal, a ninth-round pick in the 2018 draft, proved himself as a reliable top-of-the-rotation pitcher, while showing his potential as an ace-caliber pitcher, in 21 starts last season before a devastating arm injury Aug. 1, 2022.

He underwent flexor tendon surgery Aug. 17, 2022, in Los Angeles.

"I'm healthy, and it was fun to go out there and compete," Skubal said. "That's kind of what the goal was, to feel good coming out of it, and I do. I'd say that's a success. ... The nerves were definitely there, but it was good to get back out there and do what I do."

Last season, Skubal posted a 3.52 ERA with 32 walks and 117 strikeouts across 117⅔ innings. He had a 2.33 ERA over 65⅔ innings in his first 11 starts, making him an early candidate for American League Cy Young, and tossed 17 innings without an earned run in his final three starts.

After the injury, there were 335 days between his starts for the Tigers.

"He's a competitor," said catcher Jake Rogers. "I knew as soon as he stepped on the mound that whatever I called he was going to try to blow it by them. He did really well today. He didn't miss a beat."

On Tuesday evening, Skubal took the mound in the top of the first inning against the Athletics at Comerica Park. Twenty-six thousand seven hundred forty-nine fans arrived at the ballpark to celebrate the Fourth of July, and Skubal's return to the starting rotation.

Skubal fired a 94.7 mph fastball, his slowest fastball, for the first pitch of the game.

"From pitch one, I was just focused on throwing a strike," Skubal said. "That one was 94, and I'm like, 'OK, I'm ready today.' It's good to have the work that you've been working on show in the game."

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He struck out the first batter he faced, Esteury Ruiz, with a 95.9 mph fastball for a called third strike.

Skubal recorded a pair of swinging strikeouts in the second inning: Shea Langeliers (97.9 mph fastball) and Ryan Soda (89.6 mph slider). He added two more swinging strikeouts in the third inning: Manny Pina (87.4 mph slider) and Nick Allen (98 mph fastball). His 89.6 mph slider struck out Ruiz swinging to begin the fourth inning for his sixth and final strikeout.

Only one batter, Brent Rooker, reached safely when a slider hit him in the foot with two outs in the fourth inning.

His start ended after four no-hit innings.

"I mean, I wasn't going nine (innings)," Skubal said, when asked about leaving the game with a no-hitter intact.

From a health standpoint, Skubal felt like he could have pitched deeper into the game, but the short start was planned. The Tigers will ease their most valuable pitcher into the full workload of a starter at the highest level.

"We're well aware this is his first start coming off a major injury and a conservative ramp," Hinch said before Tuesday's game. "He's not going to go nine innings. He's not going to throw a no-hitter. He's not going to set any personal records. ... It's like late March, early April for him."

Skubal threw 25 four-seam fastballs (44%), 17 sliders (30%), seven changeups (12%), five sinkers (9%) and three knuckle curves (5%). He generated nine swings and misses with three fastballs, three sliders, two changeups and one sinker.

The hard-throwing southpaw fired 41 of 57 pitches for strikes.

"I thought my command was pretty good," Skubal said. "I threw a ton of strikes today. I refined my mentality of just attacking guys over the plate and letting them hit my pitches. I'm going to throw strikes, and if you can hit it, you can hit it, and if you can't, you can't. Getting that mentality hammered out has been huge for me."

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At times, Skubal struggled last season.

He logged a 7.46 ERA over 35 innings in seven starts from June 12 through July 13. The seven starts occurred between his first 11 starts and his final three starts. In those outings, Skubal couldn't capture the preferred shape of his slider. In those outings, his slider profiled like a cutter.

But Skubal had the perfect slider in his return from the injured list.

"That's kind of been the goal," Skubal said. "When I struggled last year, it did turn into a cutter there, and then I got the shape back, and the results went back into my favor. Not saying that's the reason, but having that pitch gives me a ton of confidence."

The biggest improvement has been Skubal's fastball velocity. He tweaked his mechanics under the instruction of pitching coach Chris Fetter and assistant pitching coaches Robin Lund and Juan Nieves.

His four-seam fastball averaged 95.8 mph in five rehab starts, in which he posted a 1.23 ERA with three walks and 20 strikeouts across 14⅔ innings for High-A West Michigan (two starts) and Triple-A Toledo (three starts). In his first MLB start, Skubal's fastball averaged 96.4 mph and maxed out at 98.4 mph against the Athletics.

Last season, however, his fastball averaged just 94.1 mph.

"Being able to tweak (my mechanics), take it into the game and have it show has been huge," Skubal said. "It's been a boost of confidence a little bit, too. And it feels easier to me. It doesn't feel like I was exerting more to get the velocity. It's just, that was my velocity."

Despite Skubal's success, and the success of right-hander Reese Olson out of the bullpen, the Tigers failed to provide any run support. Skubal and Olson combined for nine scoreless innings with one hit, one walk, one hit-by-pitch and 11 strikeouts.

The offense finished 0-for-10 with runners in scoring position.

The Tigers lost in a miserable way, but at the same time, it almost felt like the Tigers won because of Skubal's dominance — and noticeable improvements — in his return from flexor tendon surgery.

"Physically, I felt good," Skubal said. "My arm feels great."

Contact Evan Petzold at epetzold@freepress.com or follow him on Twitter @EvanPetzold.

This article originally appeared on Detroit Free Press: Detroit Tigers Tarik Skubal returns: He can be 'one of the best pitchers'