Mark Leiter ‘as advertised’ in impressive debut with Yankees

PHILADELPHIA — Al Leiter described his nephew as “fearless” on Tuesday afternoon.

A few hours later, fresh off the plane, Mark Leiter Jr. took the mound for his Yankees debut and proved it.

After being acquired from the Cubs a few hours before Tuesday’s trade deadline, Leiter arrived at Citizens Bank Park around game time and then tossed a scoreless bottom of the 10th to help the Yankees capture a 7-6, 12-inning win over the Phillies.

“It’s been a crazy day, for sure,” said Leiter, the son of former Yankee Mark Leiter Sr. and nephew of former Yankee and Met Al Leiter. “Just finding out and getting here during the game and then getting out there and getting in the game — really happy to see us get a win and get to celebrate with the team. It’s easy to get to know the guys when you win. It was definitely an interesting day for me.”

Leiter still had not met most of his teammates by the time he entered the game in the 10th inning.

But he got a groundout and a pop-out before issuing an intentional walk and allowing a single off his glove to load the bases.

Unperturbed, Leiter extended the game one pitch later by getting Bryson Stott to fly out.

“Looked as advertised right away,” manager Aaron Boone said. “Threw him off the plane and right into the action.”

The addition of Leiter, which cost prospects Jack Neely and Ben Cowles, brought the Yankees some swing-and-miss to a bullpen that has been largely lacking it.

The right-hander had a 4.21 ERA across 39 games and 36 ¹/₃ innings with 53 strikeouts this season with the Cubs.

His 36.7 percent whiff rate and 34.9 percent strikeout rate — the latter ranking 11th among all major league pitchers with at least 100 plate appearances against this season — became tops in the Yankees bullpen.

Besides racking up strikeouts and being known for an elite splitter, though, Leiter also arrived with some intangibles.

“The big thing that I know of him since he was a little guy is he’s fearless,” Al Leiter said Tuesday by phone. “He is not intimidated by anything. And he’s relentless. He does his thing. I think that mindset is going to put him in a good spot. I think it’s going to be a really good place in that clubhouse and for that team. I think he’s ready for it, for sure.”

Asked where that mindset came from, Al Leiter chuckled.

“Where do you think?” he said. “His dad, he was aggressive. I was aggressive. It’s in you, the DNA, of attack and being relentless. He is that and it shows. He wears his emotions on his sleeve like his father. He’s got a high level of give-a-shit, which is great. I think he’s going to do well. We’ll see. I’m happy for him.”

A 33-year-old native of Toms River, N.J., Leiter is under club control through 2026.

He missed two weeks on the injured list recently with a forearm strain — five years after undergoing Tommy John surgery — but came back on July 9 and has not allowed a base runner since, tossing 7 ²/₃ perfect innings with 14 strikeouts.

“I just think more than anything, he’s a good pitcher,” Boone said before the game. “Strikeouts or not, this is a guy that’s put together two really good years. Feel like he’s thrown the ball as well as even through those two years — not a lot of hits, doesn’t walk a ton of guys, and a lot of swing-and-miss there — he’s also thrown the ball really well this last month. That’s intriguing.”

Leiter has also excelled against left-handed hitters — another area of need — holding them to a .213 average and .657 OPS in his career.

A 33-year-old native of Toms River, N.J., Leiter is under club control through 2026.

He missed two weeks on the injured list recently with a forearm strain — five years after undergoing Tommy John surgery — but came back on July 9 and has not allowed a base runner since, tossing 7 ²/₃ perfect innings with 14 strikeouts.

Leiter cost the Yankees relief prospect Jack Neely and infield prospect Ben Cowles, both of whom were going to have to be added to the 40-man roster this offseason to be protected from the Rule 5 draft.