Takeaways from Phillies’ 8-2 run: More of Orion Kerkering, Nick Castellanos keeps swinging, and more

SAN DIEGO — The Phillies are 8-2 over their last 10 games. They have a winning record in April — 16-10 — and some encouraging trends are starting to emerge. Over the past week, they’ve posted a .281 batting average — third best in baseball — a .349 on-base percentage and a .455 slugging percentage, which both rank fourth.

Their starting pitchers have combined for a 2.12 ERA over 26 games with an MLB-best .184 batting average against. Three of their five starters have an ERA under 2.00: Zack Wheeler, Ranger Suárez, and Spencer Turnbull (although, Turnbull may be moving to the bullpen soon).

Regardless, it is a much different place than they were in about two weeks ago. As they embark on the last two legs of their 10-game road trip in San Diego and Los Angeles, here are a few observations over the last few games.

Reliever Seranthony Domínguez has allowed three home runs this season and all have come on his slider, the pitch he throws 26.4% of the time. It seems to have more horizontal movement than it had last year, with less drop. Without getting overly in the weeds: There is less bite to it and it’s ending up higher than he wants it to.

It’s unclear why this is the case — whether it’s mental or mechanical — but manager Rob Thomson said on Thursday that the Phillies are working on “tuning up” the pitch. They would like to make it have bigger break.

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“I don’t know if that’s bleeding into he’s thinking too much about his mechanics, how he’s gripping the ball, whatever,” Thomson said. “So, yeah I think it’s more just confidence right now and putting your body on autopilot and going out and just competing. As opposed to thinking.”

It’s likely that Domínguez will see some lower-leverage spots in his next outing, to build some confidence.

In Thursday’s 5-0 victory over the Reds, reliever Orion Kerkering pitched 1⅔ innings, allowing one hit and one walk with two strikeouts. After the game, Thomson said it’s a role we could see more of from Kerkering, who told him he wasn’t tired after throwing 39 pitches.

All of those pitches were sweepers and four-seam fastballs. Kerkering added a two-seam fastball last year, but barely used it after he made his big league debut, choosing to rely more on his sweeper (at a rate of 85%). It was — and is — a nasty pitch, but hitters knew what was coming.

This year, trying to be more unpredictable, Kerkering set out to throw more fastballs. He has increased his four-seam usage to 34.9%, but is throwing sinkers only 4.7% of the time. Having three pitches to lean on could help keep hitters off-balance — and enable him to pitch deeper — so the Phillies will push him to increase that two-seam usage this season.

Nick Castellanos’ woes at the plate have been written about at length but one more thing to note is just how much he is swinging. Through 26 games, the Phillies right fielder is swinging at a rate of 61.1%, which is well above league average (47.1%) and the highest rate of his career.

That 61.1% is the second-highest rate among all qualified players in MLB. He trails only the Colorado Rockies’ Ezequiel Tovar (62.3%).

He is swinging in the zone (80.1%), and is making contact in the zone (80.3%) but is still chasing quite a bit (42.6%). Castellanos told reporters in St. Louis that he felt like focusing on chasing less messed with his swing.

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Of course, the Phillies don’t want to mess with his swing, but he could see some benefit from swinging less. There is reason to believe that if he continues to swing at such a high rate, pitchers will begin to give him fewer pitches in the zone over time (because they assume he’ll swing at pitches in and out of the zone).

Just something to keep an eye on.

Bryce Harper’s post-paternity-list home run stole the show on Thursday, but the Phillies welcomed his defense at first base, too. Alec Bohm and Kody Clemens filled in for Harper over the first three games of the series in Cincinnati, and in Bohm’s defense, he had made only one start there before this week.

But it shouldn’t be overlooked just how reliable Harper has become at the position since last year. He is tied for second among all first baseman with four Outs Above Average, according to Baseball Savant, and ranks third at his position with four Defensive Runs Saved (DRS), according to FanGraphs. Not bad for a guy who made the switch to first base last July.

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