JoJo Romero is tinkering again.

Early one morning this month, Romero watched Rob Friedman (aka Pitching Ninja) interview American League Cy Young Award winner Shane Bieber on his YouTube channel. Bieber showed Friedman the grips to every pitch he throws. Romero became intrigued with Bieber’s slider. A few hours later, he threw Bieber’s slider in live batting practice at Carpenter Complex in Clearwater, Fla., just to see what happened.

He loved it.

“Now I’ve been making it my own,” Romero said recently at BayCare Ballpark. “We’re starting to break down the metrics of it, how we can make it a better pitch overall. It’s pretty much the same slider I threw, except it’s flipped on the horseshoe. I like the concept because it allows me to stay through and over the ball. It’s allowed me to be more consistent with that movement pattern that I wouldn’t normally get. Before, if I didn’t get my finger over, the ball just kind of spun up there, like a little funnel. Once I came across this I was like, ‘Oh, that’s pretty much what I need. This is awesome.’”

Not so long ago, pitchers often needed to personally ask a pitcher how he threw a pitch. Roy Halladay famously asked Mariano Rivera to show him how he threw his cutter at the 2008 All-Star Game. Halladay later traced his grip on a baseball so if he lost the feel for it, he could pick up the ball and see what changed. Today, pitchers could have waited for Rivera to appear on Pitching Ninja’s Twitter or YouTube accounts and re-watch as needed.

“Last year, pretty much all the different grips that they had up there, I would try them out just to see what they do,” Romero said. “If one worked and I could make it my own, I would take it. I can’t remember the pitcher, but they showed a changeup on there last year and it’s the [split] changeup I throw now.”

Romero, 24, is searching and fiddling because there is always room for improvement, as he tries to establish himself in the Phillies’ bullpen. He struck out the side on 12 pitches in his big league debut last August against the Braves in Atlanta. A few weeks later, a TV camera caught him smashing an energy drink can on his arm before he entered a game at Citizens Bank Park. (He had been doing it since college, but it was the first time TV captured it.) It became a fun moment for Phillies fans, who could not attend games last season because of the COVID-19 pandemic.

Romero finished his rookie season with a 7.59 ERA in 12 appearances, although two appearances late in the season bloated the ERA. He struck out 10 and walked two in 10 2/3 innings. He has a 2.25 ERA (one earned run in four innings) in four appearances this spring, after allowing one run in one inning Tuesday in a 14-5 loss to the Blue Jays.

He could be a big part of the bullpen’s 2021 resurrection.

“What I love about JoJo is that he’s got the right headspace to pitch out of the bullpen,” Phillies catcher Andrew Knapp said. “He is not scared of anything. Fearless. That’s what I really noticed when he started. The success was great, but he was out there really challenging big names. Guys like Freddie Freeman. He’s challenging those guys.”

Romero’s stuff certainly plays in the bullpen. His four-seam fastball averaged 95.3 mph last year. Besides the four-seamer, he throws a sinker, slider and changeup.

He feels more confident than ever in that four-pitch mix.

“Over the past year, I’ve gained a better understanding of the pitch profile of each pitch,” Romero said. “I’ve been trying to learn how I can maximize each pitch and work them off each other. I’ve been working on movement on each side of the plate and everything has been complementing each other. So, whether it’s a sinker or four-seamer, the changeup plays right off it. Last year was pretty much my first year throwing a changeup to lefties. I’m kind of working that into the arsenal, changeups to both sides of the plate. That kind of opened a whole new playbook for me.”

But if the playbook ever needs a new wrinkle, Romero knows help from a reigning Cy Young winner (or a countless number of other big league pitchers, for that matter) is only a click away.