Why not start Daulton Jefferies?

The Oakland A’s rotation has been the primary strength of the team this season. They lead the majors in innings and quality starts, and they’re Top 10 in both versions of WAR. One of their starters made the All-Star team, another one should have but got snubbed, and for most of the year they were five-deep with a good arm pitching every day.

However, the long summer has taken its toll. Ace starter Chris Bassitt is injured, and the rest of the group is showing signs of wear:

• Frankie Montas is as hot as ever over the past three months.
• Sean Manaea slumped in August but is back to excellent in September.
• Cole Irvin slumped for a few starts but looked good last time out.
• James Kaprielian hasn’t gone beyond four innings in any of his last three starts.
• Paul Blackburn, replacing Bassitt, held his own for three starts then got roughed up twice.

Montas and Manaea still look great, and Irvin began to allay recent concerns with his latest gem. But Kaprielian is a rookie in uncharted territory in terms of workload, and Blackburn did admirable emergency fill-in work but isn’t profiling as a sustainable long-term answer.

Meanwhile, in the bullpen, top prospect Daulton Jefferies is heating up in long relief. His last three appearances:

• Jefferies, 9/4: 2⅓ ip, 0 runs, 1 hit
• Jefferies, 9/7: 3⅓ ip, 2 runs, 1 K, 1 BB, 2 hits
• Jefferies, 9/12: 3⅓ ip, 0 runs, 2 Ks, 0 BB, 3 hits

That’s nine innings total, with two runs allowed. According to Statcast he did better in each progressive outing, for a total .319 xwOBA that rates roughly league-average.

For now, the right-hander’s role has been to eat innings after Blackburn or Kaprielian get knocked out early. So why not skip the bad part and let Jefferies start a game? After all, the 26-year-old is one of the top prospects in the system, even ranking ahead of Kaprielian last winter, so if he’s retiring MLB hitters now then it’s not unreasonable to see what more he can do.

Kaprielian is not only at a professional career-high in innings, he’s matched his entire career total in innings from the previous six seasons (albeit the same is true of Jefferies). Kap had an extremely promising rookie year and should be in the 2022 rotation, but for now he might be running out of gas. Blackburn has often been strong for his first inning or two but then hit trouble after that. Either of them could slot nicely into Jefferies’ current relief role for the rest of the year.

On the other hand, Jefferies had a great spring training, then posted his customarily strong K:BB rate in Triple-A (68:11), made one solid MLB start in early August, and is now tossing mostly zeroes out of the bullpen.

The A’s have two starters in their rotation who aren’t winning games lately, and their top starting prospect is pitching well in the bullpen. Why not make a switch and try Jefferies as a starter?