MESA, Ariz. -- There will come a point in Spring Training when Sean Manaea will put more stock into the numbers. For now, it’s all about mastering his slider, and Monday was a step in the right direction.

The results in Monday’s 14-4 loss to the Brewers don’t look great, as Manaea allowed six runs, all coming in the second inning. He was encouraged by the movement of his slider, but the location of it became an issue as the left-hander was pulled with just two outs in a rough second that put a damper on things after a flawless 12-pitch opening frame.

“Results-wise, six runs is six runs, and that sucks,” Manaea said. “I think I just left some stuff down the middle, and ultimately that was what I was trying not to do. I just wanted to get out there and throw my slider, get a feel for it. I think I accomplished that today. It’s a good starting point to work off of.”

A large part of the downfall for Manaea came from leaving fastballs down the middle when he was trying to go inside on hitters, including ones to Orlando Arcia and Lucas Erceg that were sent over the right-field wall at Hohokam Stadium for two-run homers. The homer allowed to Arcia may have also been the result of fatigue, as Manaea admitted to feeling “a little tired” in what ended up a 39-pitch outing.

“Just left some balls up,” manager Bob Melvin said. “I know he’s really trying to work on his slider. This is the time to try to do it, [but] he just didn’t really have a good one today.”

Manaea is looking to implement improvements to his slider. That includes tweaks that came on advice from Randy Johnson during a special visit to camp earlier this spring on how to manipulate the pitch and when to use it in order to throw the hitters' timing off.

“It was good. I was pretty happy with it,” Manaea said of the movement of his slider. “I was able to control it a little bit. Especially the first inning, it was good. I felt like I threw some really good ones right off my fingertips. I was really happy with it, movement-wise. Not so much location-wise.”

Hendriks adds deception
As opposed to past springs, when Liam Hendriks was battling just to earn a spot on the roster, the right-hander enters 2020 with a firm grasp of the A’s closer job. So for his first Cactus League outing Monday, Hendriks used the inning of work as an opportunity to integrate something new.

In a scoreless third inning that featured two strikeouts and required just 12 pitches, Hendriks used more of a hesitant delivery at times in an effort to catch hitters off balance. It worked to perfection against David Freitas, who froze up on a 94 mph fastball to end Hendriks’ outing with a strikeout.

“I had a little hesitation on that last pitch to him. It’s something I was working on all offseason. We’ll see how it goes,” Hendriks said. “Whether or not I implement it during the season, we’ll see.”

Hendriks referenced Angels right-hander Hansel Robles and Mets right-hander Marcus Stroman as pitchers with similar moves, though he wouldn’t plan on using it as often as they do, if at all, during the regular season.

“Just something I can add in every now and then if I’m not feeling great or have an opportunity to take advantage of a hole,” Hendriks said. “You can read guys’ swings. Some have big leg kicks and you can throw that timing off a little bit.”

The idea to add the hesitation tool to his arsenal was something that morphed after Hendriks was utilizing exercises that would help him keep better balance on the mound, something he’ll continue to work on as spring progresses.

“I’ve been a big guy who leaks or falls forward on the mound,” Hendriks said. “I need to make sure I maintain posture on the mound and keep my balance. It started as an exercise to make sure I stay back, and it grew from there.”

Hendriks said he expects his next appearance to come Thursday against the Rockies.

Jefferies leaves with injury
Daulton Jefferies, the club’s No. 12 prospect per MLB Pipeline last season and its top overall right-handed pitching prospect, entered Monday’s game to begin the fourth inning and departed with just two outs after feeling discomfort in his right biceps.

“I hope we have some good news. It was more his biceps it seems like,” Melvin said. “I’m not sure what the timeline is. I’ll talk to [head athletic trainer Nick Paparesta] now, but he didn’t come up to me during the game, which is probably a good sign. It was pretty scary to watch his reaction and to go out to see the look on his face.”

Up next
Jesus Luzardo will make his Cactus League debut as the A's travel to Peoria for a 12:10 p.m. PT tilt with the Padres. Luzardo, Oakland’s No. 1 prospect per MLB Pipeline, is set to make his anticipated move to the rotation this season after a strong showing out of the bullpen for Oakland in 2019. The left-hander has received early hype as an American League Rookie of the Year candidate. Khris Davis, who has been dealing with a calf injury, is also expected to make his Cactus League debut. The action will be live on MLB.TV and Gameday Audio.