BOSTON -- Few pitchers in baseball have matched the strike-throwing capabilities of Joey Estes, whose percentage of pitches in the strike zone (57.7%) through 10 starts this season ranked highest among all Major League pitchers with at least 600 pitches thrown.

The ability to constantly pound the zone has been a shining trait for Estes throughout his rise as a top prospect. It was on full display when he tossed a “Maddux” against the Angels last week, tossing nine scoreless innings on 92 pitches.

On Tuesday night, Estes’ aggressiveness in the zone worked against him. He recorded just five outs and allowed a career-high-tying eight earned runs over 1 2/3 innings during Oakland’s 12-9 loss to the Red Sox at Fenway Park. It marked the right-hander’s shortest outing as a big leaguer and encapsulated the typical highs and lows young pitchers experience by following up on the best outing of his career just six days prior with his worst.

“A lot of mistakes in the middle of the plate,” manager Mark Kotsay said of Estes’ rough start. “[The Red Sox] are aggressive and took advantage of Joey’s ability to throw strikes and barreled him up. Overall, one of those outings where he can learn from.”

When Kotsay went to the mound to take the ball from Estes after Connor Wong’s two-out single in the second, the skipper put his arms around Estes and spoke to him for several seconds before sending him back to the visiting dugout. During his postgame media session, Kotsay revealed that Estes had been dealing with a stomach illness that may have hindered him a bit.

“Not to make any excuses for the kid,” Kotsay said. “But he wasn’t a hundred percent. He went out there and pitched as best he could. … I just told him to keep his head up. He gave us everything he had. I knew he was hurting. We tried to push him as far as he could. Unfortunately, it just wasn’t his night.”

The average velocity on each of Estes’ five pitches was down about a tick below their season average. That along with a lack of execution led to plenty of hard contact throughout the night for the Red Sox, who began the game with four consecutive hits off Estes, three of which registered an exit velocity of 106 mph or harder.

Estes acknowledged that he felt debilitated on the mound as a result of the illness but did not use it as an excuse, instead chalking up his struggles to a lack of feel for any of his pitches.

“I just didn’t have my [stuff] today,” Estes said. “I couldn’t get first-pitch strikes. I couldn’t land my offspeed for strikes. I just kind of got hit around. The pitches that they hit were just left in the middle. Even some pitches I threw well, they still hit them. They’re a good hitting team.”

Between his complete-game shutout on July 3 and a perfect game bid into the seventh inning on June 5, there have been enough flashes this season for the A’s to believe Estes has a bright future as a long-term piece of their rotation. But in some ways, taking the lumps that he did on Tuesday is almost as important for his development because of the learning experience they provide.

“I had [an outing like this] not too long ago in Minnesota,” Estes said, recalling a start against the Twins at Target Field last month in which he was tagged for six runs in 2 2/3 innings. “This reminded me of that a little bit. I didn’t really have that feel [of my pitches]. The ball was slipping out a little bit. You learn a lot from these games. I just have to keep going and put this one behind me. Get after the next one.”

Considering the A’s were trailing 11-2 after two innings, their offensive resilience was a positive takeaway. Oakland remained competitive throughout the night and clawed its way back with seven runs over the final four innings, including a pair of three-run home runs by Lawrence Butler and Zack Gelof. Butler’s 457-foot shot was the longest of his career and the longest by an A’s player so far this season.

“I tip my cap to the offense for grinding at-bats out,” Kotsay said. “The grit they showed tonight. Not to quit in a game where they easily could have just gone up and thrown at-bats away is a testament to the character in the room.”