In search of a boost for the back end of their bullpen this offseason, the Angels addressed that need by landing one of the top remaining free-agent relievers available in right-hander Robert Stephenson.

The three-year deal, which was officially announced on Tuesday, is worth $33 million and includes an injury clause that adds a $2.5 million club option for 2027 if Stephenson were to sustain an elbow injury that required a stint on the injured list for at least 130 consecutive days.

Stephenson underwent a transformation when the Rays acquired him last June in a deal with the Pirates. Upon joining Tampa Bay’s renowned pitching development program, the 30-year-old was able to maximize his strengths after some mechanical tweaks. The result: Stephenson posted a 2.35 ERA in 38 1/3 innings with the Rays while striking out 60 batters and allowing just eight walks. From June through the rest of the season, his 37.1 percent strikeout-minus-walk rate was second-best among all pitchers (min. 30 innings) behind only Félix Bautista’s 37.6 percent mark.

“One of the things you look for from a player, especially from a scouting standpoint and just tracking a player over the course of time, is improvement,” Angels general manager Perry Minasian said. “He went to Tampa last year and was one of the best, if not the best, reliever in baseball over those 40 innings.”

So, what changes did Stephenson make to unlock that elite level of pitching last season? Two things. An adjustment on the release point of his slider to increase velocity and movement, and a more aggressive approach against hitters.

“Just making a little adjustment on how I release [the slider] helped add some velo to it,” Stephenson said. “I think that helped a ton on just putting the pitch in the zone more often and getting more swing and miss on it. Moving forward, I feel like that’s sustainable because it’s a better version of that pitch. Another thing we also played around with was just the way I attacked hitters. Trying to put guys in a hole quicker. I think that helped a lot, too.”

There was no shortage of interested suitors on Stephenson’s services this offseason. But one important deciding factor the Angels had an upper hand on was location. Stephenson, who was born and raised in the Bay Area in Martinez, Calif., has pitched on the East Coast for most of his eight-year big league career. Joining the Angels allows him to be much closer to his wife, Jaime, and two children.

“It’s awesome to have the opportunity to be so close to home now,” Stephenson said. “Being on the East Coast was great and I loved it out there, but it was a little bit of a challenge for my family to get out there. I’ve got two little kids, so being able to see them makes a world of difference.”

Stephenson figures to slot into a late-inning role alongside All-Star closer Carlos Estévez and high-leverage options such as right-handers Ben Joyce and José Soriano, as well as recently added righties Luis Garcia and Adam Cimber. The group could certainly use an improvement. Last season, the Angels bullpen posted a 4.88 ERA and particularly struggled in high-leverage spots late in games with a combined 5.28 ERA in the sixth, seventh and eighth innings.

“We had a hard time in the sixth, seventh, eighth inning,” Minasian said. “For us to win more games, and especially compete, we have to be better in those middle innings. Adding a Stephenson, you try to push as many guys as you can down the pecking order. Stephenson gives us another high-leverage guy where [manager Ron Washington] can use him where he wants to and more depth in the bullpen, which we felt like was needed.”

While the Angels could still look to add another lefty in the bullpen, the addition of Stephenson likely shifts their focus back to their rotation, where they have been in contact with free-agent starters such as Blake Snell and Jordan Montgomery.

“We’re definitely not done from an offseason standpoint,” Minasian said. “It’s got to make sense and be the right fit. I do believe there are still players out there that can help us improve and make us a more competitive club.”