DETROIT -- There is a lot the A’s have liked about Hogan Harris in his first taste of big league action. His final start before the All-Star break, however, was a reminder of the growing pains that a rookie must go through.

Making his ninth appearance of the season and his fourth career Major League start, Harris took his lumps. In Thursday’s 9-0 loss to the Tigers at Comerica Park, the left-hander was tagged for a career-high seven runs on eight hits and four walks over 4 2/3 innings.

“For Hogan today, [the Tigers] just hit him,” A’s manager Mark Kotsay said. “He pounded the zone. I know his strike percentage was pretty high. I think they just had a great offensive approach against him today. The walks mixed in kind of hurt him a little bit.”

Consistently throwing strikes can be easier said than done for a young pitcher. Even in a rough one against Detroit, Harris still maintained that quality of his game, delivering 69 of his career-high 105 pitches for strikes.

On Thursday, Harris’ feast-or-famine fastball was the tale. Throwing it 64 times, the most fastballs he’s ever thrown in an outing, Harris produced 34 strikes and 12 whiffs on the pitch. When hitters were not swinging through it, though, they hit it hard, with an average exit velocity of 97.1 mph on the nine fastballs hit in play against him.

“I got a decent bit of swing-and-misses, so that’s a plus,” said Harris, who finished with 15 total whiffs. “It was just pretty much everything else. All the other strikes I threw weren’t quality strikes. Either they swung and missed or they hit it pretty hard somewhere. 

“It was one of those days. Baseball is a weird thing. Today it felt like they either missed or hit it 110 mph. I tried to battle out there. Sometimes it gets the better of you.”

Harris will enter the All-Star break having shown considerable growth since his forgettable Major League debut on April 14. Prior to Thursday, he carried a 3.79 ERA while limiting opponents to a .229 batting average and .676 OPS in 38 innings over his previous seven outings. Four of those games saw him pitch at least five innings and allow two earned runs or fewer.

“I would say that I’ve competed pretty well,” Harris said. “I’ve made multiple little adjustments, whether it be motion or mindset. It was kind of nice in the aspect that there are things I can take away and keep going for the second half. A couple of things that didn’t work too well and we can go back and forth. Ideally, we get a good blend of everything and just crush it in the [second] half.”

With Thursday’s outing inflating his ERA to 6.07, there are some obvious areas of improvement for Harris.

“Eliminating the walks and the free bases,” Kotsay said. “Maybe a little bit better command. But from what we’ve seen recently, I think he’s making the right progress. You’re going to have an outing like this when you get hit. But he’s moving in the right direction.”

Harris echoed similar sentiments when addressing what he would like to improve for the second half, also adding that improving the quality of his cutter is going to be a key going forward.

For the season, opponents are hitting .325 against the 149 cutters thrown by Harris, a stark contrast from the .177 batting average against hiss 277 fastballs and .200 average off his 119 changeups. Against Detroit, he threw just eight cutters and struggled when trying to use it as a means of getting ahead in the count.

“That cutter is staying too over the plate for me right now or running arm side,” Harris said. “Ideally, I hone that back in. I’m happy with the swing-and-miss I’m getting, but I’m not getting as many ground balls. I’m hoping to get a few more whenever we need a double play. I feel like I did that well for a couple of games. The walks are not as bad as they have been in the past, but they’re kind of lingering back in. Just get my rhythm mechanically.”

Harris, Oakland’s No. 20 prospect, will get ample time to work on those adjustments, with his next start likely coming against the Red Sox in Oakland’s second series back from the break.