Joan Adon’s demotion is part of Nats’ rebuilding process

Adon posted a 6.95 ERA in those outings, a number that spiked after the Miami Marlins scored eight in three innings against him Tuesday. He walked 35 batters in 55⅔ innings, the most among pitches who have thrown at least 50. He mostly throws two pitches, a four-seamer and curve, and has to develop his change-up and maybe a secondary fastball with the Class AAA Rochester Red Wings. Before April, he had pitched only 23 innings above high-Class A. Needing more time in the minors doesn’t mean he can’t excel in the future.

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“Honestly, this was kind of like by design. This is something that we talked about in spring training that might happen,” Manager Dave Martinez said before Wednesday’s 2-1 loss to the Marlins in Miami. “But I think it’s important that he understands that he’s really done nothing wrong. Take away the results. He’s a young kid that’s learned.

“Unfortunately, this is a result-driven business, and he understands that, too. So it’s his job to go down and just get better and come back up and be ready to go again.”

The Nationals’ current rotation is Strasburg, who returns Thursday, Corbin, Gray, Erick Fedde and an opening. Martinez told reporters the club might stretch out both Lee and Paolo Espino because of a doubleheader against the Philadelphia Phillies on June 17. Yet if Lee keeps starting, that means Washington (21-37) will continue tapping at least one rotation spot for development purposes.

And why not? Joe Ross will undergo Tommy John surgery Friday and is out for the rest of the season. Aníbal Sánchez, 38, remains sidelined with a cervical impingement in his neck. Plus, injured veterans aside, General Manager Mike Rizzo said during a Wednesday radio appearance on 106.7 The Fan that the club will likely trade most players who are desired and on expiring contracts this summer.

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Lee, a 24-year-old lefty, debuted against the New York Mets on June 1 and logged five outs out of the bullpen Tuesday. Adon’s next appearance will come in Rochester, where Cavalli and fellow top prospect Cole Henry are also in the mix. If Adon can’t add a third pitch to his arsenal, his ceiling lowers considerably, potentially making him a reliever down the line. And if he can’t eventually add a fourth pitch while starting — even one he doesn’t throw often — he hurts his chances of becoming more than a back-of-the-rotation/depth arm.

Adon flashed the ability to beat hitters with a mid-to-high 90s fastball. Too often, though, he was either tipping pitches or behind in counts, leaving him all too predictable. So for now, Lee gets his chance and Adon goes to where he arguably should have in April. Martinez sees no harm done.

“My message to Joan [Tuesday] was: ‘You didn’t fail. This is a learning process, and you were up here at a fairly young age,’ ” the manager recalled. “So you got to understand where he’s been. He hasn’t pitched very much and the fact that he [was] up here and pitching for us from Opening Day, making the team was huge.

“And I said … ‘Take the positives out of it. You were here. You learned a lot. You’re going to go down there with a lot more experience than you’ve ever had.’ ”