Kenley Jansen, who signed with Boston in the offseason, is among the slowest pitchers in baseball and is trying to prepare for this season’s new pitch clock. Brett Davis/Associated Pfress

FORT MYERS, Fla. — New Red Sox closer Kenley Jansen isn’t hiding the fact that he has always worked at an extremely slow pace. He knows it will take time for him to adjust to the pitch timer MLB is implementing this season.

“As much as I want to compete for the World Baseball Classic, I just want to make sure – knowing that I’m the slowest guy in the league – I want to adapt to that quickly,” Jansen said here at JetBlue Park on Wednesday. “That’s why I choose to make sure I’ll be here in camp. And like I say, get to know my teammates and also adapt to certain stuff.”

The Red Sox finally added an established closer, inking Jansen for two years at $32 million. But there’s one problem. He had the third worst tempo (25.6 seconds) between pitches last year, behind only Jonathan Loáisiga (25.8) and Giovanny Gallegos (25.8), per Baseball Savant.

He led all pitchers for the worst slow percentage (22.3%) with the bases empty. He was second worst in slow percentage (57.3%) with runners on base.

“I‘d love to go play for Netherlands,” he said. “I also want to be here and know my crew. And also adapt to the pitch clock.”

Netherlands begins WBC pool play in Taiwan as part of Pool A. Jansen is part of Netherlands’ designated pool. So he will join the team if it makes it to the semifinals in Miami.

Pitchers will have 15 seconds between pitches with the bases empty and 20 seconds between pitches with runners on base. Jansen said he worked with a pitch timer during the offseason to prepare.

“It’s gonna be challenging on both sides,” Jansen said. “It’s not only going to be on pitchers but I think hitters are going to be uncomfortable, too. Sometimes when they fall behind 0-2 or 0-1 quick, they take their time, too. So it’s both ways. So both ways have to adapt. It’s not only pitchers. So it’s gonna feel fast, and we all gotta go figure out how to slow the game down in certain ways to not let the game speed up on you and things get out of hand.”

MANAGER ALEX Cora was surprised by Adalberto Mondesí’s size when he first saw him here at spring training.

“Wait till you see him,” Cora said. “I thought he was like smaller. But he’s like Xander-esque as far as like tall, strong, big legs.”

Boston acquired Mondesi, a second baseman/shortstop, from the Royals on Jan. 24. The 27-year-old is returning from ACL surgery he underwent last May. He was limited to just 15 games in 2022.

Mondesí, Kiké Hernández and Christian Arroyo are the only experienced middle infielders on the 40-man roster. Hernández will start at shortstop. Cora said Tuesday that Arroyo is Boston’s starting second baseman “as of now.”

Chief baseball officer Chaim Bloom said he wouldn’t bet on Mondesí being ready for Opening Day. He said that’s the best-case scenario.

“(Mondesí) was running yesterday and you can see it. He’s elite in speed,” Cora said. “He’s running at 70% and you can see it. Dynamic, good defender. We still have to work on the offensive side of it just to make sure he gets on base at a higher rate. But this guy, I saw one season his on-base percentage was .308 and he stole 24 bags so the stolen base aspect is real.”

Mondesí led the league with 24 steals during the shortened, 60-game 2020 season. He has dealt with injuries throughout his entire career, limiting him to 358 games over seven seasons.

He had 43 steals and a league-leading 10 triples in 102 games in 2019. He stole 32 bases in 75 games in 2018.

Mondesí, once ranked by Baseball America as the No. 28 prospect on its Top 100, has batted just .244 with a .280 on-base percentage, .408 slugging percentage and .687 OPS as a major leaguer.

“The defense is really good,” Cora said. “The offensive part of it, we’ll help him. He can bunt whenever he feels like. So we’re excited about it. We’ll use the three of them, you know, the right way when everybody is healthy. We’ve just got to make sure everybody’s healthy.”