Dodgers’ Kenley Jansen, Angels’ Ernesto Frieri join the fan club

The realization of what had just happened didn’t immediately sink in for Tony Gwynn Jr.

It wasn’t until Gwynn was back on the Dodgers bench, after he had struck out against Cincinnati Reds closer Aroldis Chapman on Monday night, that Gwynn thought about the pitch that narrowly missed his hand and struck the knob of his bat instead.

“If that ball hits my hand, my hand is shattered at 101 mph,” Gwynn said Tuesday. “I just thought, thank you God for not letting that ball hit my hand.”

Chapman is the 24-year-old Cuban left-hander who routinely unleashes fastballs clocked at 100 mph-plus, and he’s one of the current crop of relief pitchers who mostly rely on blazing speed rather than guile to get batters out, often by striking them out.

Others include closers Kenley Jansen of the Dodgers, Ernesto Frieri of the Angels and Craig Kimbrel of the Atlanta Braves, to name just a few. Each sends a simple message to batters: “Hit it if you can.”

Jansen last year set a major league record by averaging 16.1 strikeouts per nine innings of work. This year, the 6-foot-5, 260-pound right-hander is averaging 14.3 strikeouts per nine innings entering Tuesday’s play, third in the National League behind Chapman (15.9) and Kimbrel (15.0).

Frieri is averaging 15.5 strikeouts per nine innings since he joined the Angels in early May, tops in the American League among relievers.

But while the strikeout is key for these relievers, mere heat isn’t always enough against big league hitters. Chapman blew back-to-back saves last month, giving up a two-run walk-off homer in the ninth inning of each game. Frieri hasn’t yet allowed a run as an Angel, but is averaging a 5.5 walks per nine innings, while Chapman, Jansen and Kimbrel — the NL leader in saves with 23 — average about three.

That’s why, Jansen said, “my whole thinking is strike one. Strike one will change the whole at-bat.” The reasoning is simple: If the batter quickly falls behind in the count, it’s an advantage for Jansen, who has 12 saves in 15 chances.

Plus, he said, “if I’m ahead in the count I still have a lot of places to miss” with the next pitch. “When I get two strikes, that’s when I have a little more in my tank and I try to sneak [the third strike] in there.”

Indeed, Jansen and Chapman said that while it might appear they’re throwing each fastball as hard as possible, they keep an extra ounce of oomph in reserve.

“You have something in reserve for when you have to throw harder to get the guy out, yes,” Chapman, who this week was selected for his first All-Star game, said through an interpreter.

That’s a daunting thought for batters. But Torii Hunter, the Angels’ veteran outfielder, said, “I don’t want to say [it’s] intimidating. I think like, ‘I’m going to get you.’ You can never walk up there and second-guess yourself.”

Chapman said that with each batter, “all I want is to just get the out . . . sometimes, if there’s a two-strike count, then you try to strike him out.”

Frieri, speaking in Spanish, said he does not try to strike out every batter. “The truth is, no, I just try to attack the strike zone and have the batter put the ball in play because we have a good infield, good outfielders,” he said.

“When I’ve wanted to strike batters outs that’s when I’ve had problems,” said Frieri, who has 10 saves, all with the Angels. “I just try to attack the strike zone and have them put the ball in play.”

What makes these hard-throwing closers even tougher to face is when they mix in an occasional breaking ball.

“The hitters tell you when to use” a curveball, slider or other breaking pitch, usually if they’re looking too comfortable waiting for the fastball, Jansen said.

“Sometimes when I feel like it, I throw a breaking pitch to keep them honest,” Jansen said. “It’s a guessing game — make them think I might come with it again and not let them stay on my fastball the whole time. You cannot stay in one gear.”

Batters called on to pinch-hit in the ninth inning perhaps have it the toughest against the likes of Jansen.

“You haven’t swung a bat in like two hours, three hours [and] go up there and face a guy throwing 95-plus,” Hunter said. “You’re going up there naked.”

But at least you’re probably not staying up there for long.

james.peltz@latimes.com

Times staff writer Kevin Baxter contributed to this report.