Oakland A's option starter Daniel Mengden, call up reliever J.B. Wendelken

After already activating catcher Stephen Vogt earlier on Tuesday, the Oakland A's made another move by optioning starting pitcher Daniel Mengden to Triple-A (via Jane Lee of MLB.com). To take his spot, they called up right-handed reliever J.B. Wendelken.

Mengden burst onto the MLB scene in June after sprinting his way up the system all the way from Double-A. His first four starts went beautifully (2.81 ERA), but things caught up with him in July and he hit a rough patch (9.00). Even when he's struggled, though, there is a lot to like about Mengden, from his consistently high strikeout rate (1 per inning) to his ability to string together multiple dominant innings. More than one of his poor starts was also affected by some outside factor, like getting drilled in the chest by a line drive or getting squeezed by an oddly terrible Mark Wegner strike zone or having his defense cost him outs.

It's not unusual to see a talented young pitcher go through growing pains, and it didn't help that Mengden was probably rushed a bit to bolster Oakland's trainwreck of a rotation. We recently saw Sean Manaea go through his own slump after being rushed through Triple-A quickly, but he was able to make the necessary adjustments and overcome -- now he's looked great his last several times out. The fact that Mengden reached MLB at all this year and even held his own for a while should make you a hundred times more excited than whatever disappointment you might feel about his 5.73 ERA. What he's done this year is absolutely bananas and it's beyond a reasonable best-case scenario.

Mengden, 2016 MLB: 9 starts, 5.73 ERA, 48⅔ ip, 49 Ks, 26 BB, 5 HR, 4.31 FIP

For his part, Mengden welcomes the move, based on his quotes to the beat writers. He knows he's not getting the job done lately, and fatigue may also be playing a role given that he's only 14 innings away from setting a new career-high.

Mengden says, "It's all about executing." Understands the move and expects to be back here.

— Jane Lee (@JaneMLB) July 26, 2016

Mengden says trip to minors will allow him "to get my feet underneath me". Thinks fatigue has been issue. A's want him to get velo back up.

— Joe Stiglich (@JoeStiglichCSN) July 26, 2016

Indeed, Mengden has lost a tick or two on his fastball in his last couple games, according to Brooks Baseball.

Mengden feeling a bit run down - #Astros limit minor league starters IP, since coming to #Athletics org he's pitched full season to point.

— Susan Slusser (@susanslusser) July 26, 2016

RHP Daniel Mengden confident he will be back soon with #Athletics. He is looking to recover from "being banged up all the way around."

— John Hickey (@JHickey3) July 26, 2016

Bottom line, this seems pretty routine. A 23-year-old pitcher came up, had his first trial, did some good things and some bad things, and now he's dipping back down to the minors for a breather and to make adjustments. He'll be back, if not later this year then definitely next season.

As for the rest of the rotation, this is the second time in as many days that the A's have sent down a starter -- Jesse Hahn was optioned on Monday after his spot start the previous day. That leaves Manaea, Sonny Gray, and Kendall Graveman as reliable options, with Rich Hill's status up in the air while his blister heals. The A's have off-days on Thursday and Monday, though, so if there was ever a time to go light on starters this would be it. Zach Neal, currently the long man in Oakland's bullpen, can also start in a pinch if needed, and Hahn and Dillon Overton are ready in Triple-A (other than waiting through the minimum 10-day period between being sent down and called back up).

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As for Wendelken, this will be his third stint in Oakland, though he didn't make it into a game his last time up. In two MLB appearances he has allowed five total runs, but to be fair the focus in his outings was more on desperately trying to get the team through nine innings rather than putting the rookie in a position to truly succeed. Here was my takeaway from his MLB debut in May, against the Orioles (names added in parentheses for clarity):

Thanks to the grand slam, he now has an unsightly 27.00 ERA to open his MLB career. However, if that's all you look at then you will be selling his performance short. He struck out a pair of All-Star sluggers (Wieters and Davis) and got beat on a mistake pitch by the current best hitter in baseball (Machado). It could have been worse, and I'll be interested to see how he looks his next time out.

Wendelken's bread-and-butter pitch is his excellent changeup, which he sets up using a merely decent 91-92 mph fastball (topped out at 93 in his debut). The 23-year-old righty joins an ever-changing pen that currently features:

- Madson (closer)
- Dull
- Axford
- Rzep (L)
- Hendriks
- Coulombe (L)
- Neal (long man)
- Wendelken

And finally, his numbers for Triple-A Nashville this year:

Wendelken, 2016 AAA: 33 games, 4.66 ERA, 36⅔ ip, 51 Ks, 21 BB, 5 HR, 4.73 FIP