Coming into this past offseason Justin Slaten had only ever pitched five games above Double-A, but what he’d shown was so tantalizing that when he was left unprotected from the Rule 5 Draft, the Red Sox made him their primary (and only) target.

Two weeks into his rookie season, you’d probably think Slaten’s been pitching in the big leagues for years.

The 26-year-old right-hander has proven himself an absolute steal, and through his first six MLB games he’s posted a sterling 0.87 ERA over 10.1 innings. He’s held opposing batters to a minuscule .094 average, and on Sunday he delivered arguably the most important relief outing of the season, drawing a must-have double play on one pitch to escape a sixth inning jam before going 2.2 innings in the club’s eventual 5-4 win over the Los Angeles Angels.

Slaten didn’t allow any earned runs in spring training either, and this week the rookie acknowledged that his big league journey has gotten off to as good a start as he could have ever anticipated.

“It feels good to be throwing well right now, the only thing I’m trying to do is come in and throw strikes. That’s really all you can do,” Slaten said before crediting teammates like Garrett Whitlock, Chris Martin and Kenley Jansen for their leadership. “Really since I showed up in Fort Myers they’ve helped me and talked to me about what it’s going to be like and what you’ve got to do to compete.”

How has Slaten been so successful? Slaten epitomizes everything the new Red Sox braintrust values in a pitcher. He fills the strike zone with nasty stuff, and he brings the kind of consistent, level-headed approach that has allowed him to capitalize on his big opportunity without getting overwhelmed by the big stage.

“His ability to be in the strike zone early and attack, hunt, hunt first pitch strikes, hunt outs,” said pitching coach Andrew Bailey. “The mindset he has, he’s very carefree, a very stoic type of demeanor, it seems like he’s been out there for years. He’s got really good stuff, he’s very talented as well, so credit to him for the work he put in in the offseason taking advantage of the opportunity.”

“He doesn’t get too emotional,” said manager Alex Cora. “He got the double play, we were all excited in the dugout and he’s like I’ve got to go back and get three more outs. He’s a good one, he’s really good.”

In many respects Slater’s journey has mirrored that of Whitlock, who was also a Rule 5 pick who enjoyed a historically dominant rookie season back in 2021. Slaten currently occupies the same multi-inning relief role Whitlock started out in, but while Whitlock said he’s been happy to offer the rookie advice, Slaten deserves all the credit for everything he’s accomplished.

“All the veterans probably appreciate he’s saying that they’re helping him out, but he’s doing it himself,” Whitlock said. “I’m extremely proud of him and I’m sure everyone else would say the same thing.”

His teammates echoed that sentiment.

“He’s nasty man, he’s nasty,” Jansen said. “He’s going to be great man.”

As a Rule 5 pick Slaten has to stay on the Red Sox big league roster for the entire season or be offered back to the Texas Rangers, but at this point it doesn’t look like he’s in any danger of going anywhere. There will inevitably be some bumps in the road, but Slaten has shown from day one that he belongs, and he should have a long and bright future in Boston ahead of him.

“I know eventually I’ll give up runs and hopefully I’m around long enough to give up a lot of runs,” Slaten said. “It’s one of those things in this game where it’s going to happen and you just have to try and make sure when it rains it doesn’t pour.”