How Joe Boyle's IL trip will affect the Oakland Athletics' rotation

On Monday afternoon, the Athletics announced that they were placing Joe Boyle on the 10-day IL due to a lower back strain. In a corresponding move, the A's recalled left-hander Hogan Harris from Triple-A to take Boyle's spot on the active roster.

Harris threw 63 innings in Oakland last year, pitching to a 7.14 ERA with a slightly more encouraging 5.02 FIP. As with what seems like all Athletics' pitchers, Harris walks too many batters and allows far too many home runs.

In the small sample of 2024, he's posted a 9.00 ERA with a 19% walk rate and has given up 5 home runs in 21 innings pitched at Triple-A Las Vegas.

When Boyle left Sunday's start after just one inning, we assumed that he might wind up on the IL. But not many A's fans speculated that Harris would be the one to get the call.

Martin Gallegos of MLB.com reported that the Athletics are likely going to recall Osvaldo Bido as the extra man for their doubleheader against the Rangers on Wednesday. Bido has been pitching better than the other starters on the 40-man and while discussing potential options to replace Boyle on the active roster, Bido's name was at the top of the list.

That may well remain the plan. Harris won't be in line to start during the current series against the Rangers. It's possible that the A's called up Harris to provide bullpen depth during this series with Texas and will recall Bido to start on Wednesday anyway.

But unless Bido remains on the roster, that leaves the A's with just a four-man rotation, assuming Harris isn't in it.

Will the A's rely on lefty Kyle Muller to take Boyle's place in the rotation?

Muller has certainly pitched well enough to warrant the opportunity. So far in 2024, he's posted a 2.61 ERA in 8 appearances, along with a 19.5% strikeout rate and a miniscule 3.7% walk rate.

The issue with Muller is that he was so bad between Oakland and Las Vegas last year that it's tough to trust him, even after 20 innings of strong bullpen work.

However, he might be the Athletics' best option. Rule 5 pick Mitch Spence is pitching well but doesn't have any experience starting at the major league level. The righty has made 6 appearances of at least 3 innings this year so while he's not fully stretched out, he's probably close enough.

Outside of Muller, Bido, and Spence, Joey Estes is the only other starter on the 40-man that has experience pitching in the majors, and he doesn't exactly have a track record of success.

The most likely scenario feels like Muller takes Boyle's spot in the rotation and Harris pitches in the bullpen until Scott Alexander returns from his rehab stint. Bido will get the call up for Wednesday's doubleheader and will be sent back down afterward.

We'll have to wait and see how long Boyle will be out. He underwent an MRI this afternoon and the Athletics determined the injury to be severe enough to warrant a trip to the IL, but did not provide an update outside of that. We'll keep our eyes on it and update as necessary.