Mariners keeping an eye on Kirby's workload

This story was excerpted from Daniel Kramer’s Mariners Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

The Mariners are marveling at the trajectory that George Kirby is already on in what has been an impressive rookie season. But they’re also approaching the territory of how to handle his workload as the club eyes the second half of the season.

Seattle has climbed its way back toward the .500 mark, is going to be returning key offensive contributors in the coming weeks and has an Aug. 2 Trade Deadline to possibly add to the roster by. Despite shortcomings in the first half, those are promising indicators that the Mariners can be more productive in the final months.

But they’ll also need to continue to receive an elite level of production from their starting rotation, and Kirby has emerged as a key fixture among that group. The 24-year-old has a 3.75 ERA while holding hitters to a .257/.284/.456 (.740 OPS) slash line. He has also given manager Scott Servais plenty of innings, going at least six frames in six of his 11 starts and topping out at seven in Saturday’s gem, when he surrendered just three hits and struck out nine.

Yet in doing so, Kirby has already blown past his 2021 innings total of 67 2/3 by accumulating 84 2/3 this season, including his five starts with Double-A Arkansas. That’s not a bad thing, and the Mariners had long envisioned this predicament before calling him up in May. But there’s no chance that Seattle will let him continue at this rate, which has him on pace for roughly 170 innings this season. Typically, with young arms, teams add 30-40 innings from the previous year, though the leash might be longer with Kirby.

Servais even acknowledged that the club will need to get creative soon on how to manage the rookie’s workload.

“We haven’t gotten into August and September. We don’t know how it’s all going to play out yet,” Servais said. “He looks very strong to me at this point. I think you look at what he's doing in between his starts, pulling back there.”

The four off-days built in for the All-Star break will obviously help mitigate how the Mariners align their starting pitchers to begin the second half, and there are off-days this Wednesday and Monday, when they could re-slot their rotation. If they stand pat, Kirby would be in line to pitch Friday against the Blue Jays at T-Mobile Park. In theory, they could use Robbie Ray in that spot because he’d be on regular rest, then work backwards, as Chris Flexen could follow on regular rest.

They could conceivably skip Kirby twice with those two off-days, which would allow them to rest him a full two weeks until July 16 in Arlington. That seems less likely, but it’s possible.

“We’ve got the All-Star break coming up, so he'll get an extended period of downtime there,” Servais said. “He’ll probably be one of our later guys pitching out of the break.”

Making matters murkier is that they’ve gone all-in on transitioning Matt Brash to the bullpen after a tough first month in the Majors. Brash had battled Kirby for -- and won -- the final rotation spot out of Spring Training. Part of that was related to Brash’s higher innings total. He might’ve been another option to make starts when they needed to rest Kirby, but that’s not possible now that he’s completely adjusted his arm care and routine.

There are options for spot starters at Triple-A Tacoma, including Justus Sheffield and Darren McCaughan, though they aren’t nearly as effective as Kirby. And there’s always the opportunity to add at the Trade Deadline, but the Mariners’ more pressing needs are bats and extra bullpen arms.

It all adds up to making Kirby’s situation one worth watching in the coming weeks.

“We'll continue to monitor it, but when you watch him pitch like he did [on Saturday],” Servais said, “it looks like he's got plenty of gas left in the tank.”