Royals starting pitcher Brad Keller's season has come to an end with more than a month remaining on the major league schedule.

Royals manager Ned Yost announced Wednesday that the 24-year-old will not make another start for the rest of the season due to the increased volume of innings he's pitched in his first full season as a starter as well as what Yost described as "arm fatigue."

"There's nothing to gain from continuing to push him out there," Yost said. "He's going to do all his work and stuff, but we're not going to let him throw for five to seven days. Then he'll finish the year off working with (pitching coach) Cal (Eldred) on mechanical stuff that we want to incorporate going into next year."

Keller, a 6-foot-5, 230-pound right-hander who the Royals acquired through the Rule 5 Draft prior to last season, made 28 starts and pitched 165 1/3 innings this year. His previous high for innings pitched in a season had been 140 1/3 innings.

Keller posted a 7-14 record with a 4.19 ERA, .247 opponents' batting average, 1.35 WHIP, 122 strikeouts and 70 walks in 28 starts.

Yost said he saw a drop in velocity, elongated arm action and a lack of command in recent outings from Keller.

"When you add up the pros and cons, there's no pro and a bunch of cons," Yost said.

Prior to only going 1 1/3 innings in Monday night's blowout loss to the Oakland Athletics, Keller had pitched back-to-back quality starts including six scoreless innings against Baltimore on Aug. 20.

Keller entered the season with a goal of pitching 200 innings, and he said that will remain a goal in the future.

"I think me and (Jakob) Junis were both on pace to get there," Keller said. "We just happened to catch an innings limit. That's basically what happened. I feel like next year we can both get there along with the best of our starting staff."

Keller previously admitted to feeling tired late in the season, but he had chalked that up to the normal summer fatigue players experience during the course of a season. He said last week that he'd likely take more time to rest and recover this off-season before beginning his training regimen.

"I don't think anybody likes being shut down, just because of the competitive nature," Keller said. "I completely agree with what they have to say. I think it's for my best interest."