SURPRISE, Ariz. -- The Royals signed lefty Jake Brentz to a two-year Major League deal as he rehabs from left elbow surgery he had midseason last year.

The contract is fully guaranteed, a source told MLB.com, and Brentz will make $850,000 in 2023 and $1.05 million in ’24.

The 28-year-old reliever from St. Louis made his MLB debut in 2021 with Kansas City and pitched in high-leverage situations throughout the year. Brentz went 5-2 with two saves and posted a 3.66 ERA across 64 innings as a rookie, leading the Royals with 72 appearances.

“We made it pretty clear that I wanted to be here,” Brentz said Friday. “I want to play here for the rest of my career. I love my teammates, the organization, the staff. I made it clear I wanted to be here, and there was really no other thought to play anywhere else. But we had to be patient and work through the details. I’m glad it worked out.”

Brentz opened the 2022 season with Kansas City, but he pitched in only eight games while trying to play through injury. He went on the injured list at the end of April with a left flexor strain. After trying to come back without surgery, Brentz eventually had season-ending Tommy John surgery at the end of July. A typical recovery from that procedure is one year, so Brentz could make rehab appearances in the second half of this season. He’s throwing at a distance of 75 feet now, and if all goes well, he should be throwing off a mound by the end of May and in games in July.

“I have just been taking it day by day and focusing on the little things,” Brentz said. “Focus on your mobility. Every rep matters when it comes to strengthening your scaps or your shoulder, getting the elbow back to full range of motion. [I'm] mentally sticking to the process and knowing that I’m going to come back stronger because of this.”

Brentz elected free agency shortly after the Royals designated him for assignment in November, but Kansas City was always interested in bringing him back. The two-year Major League deal keeps Brentz in the organization after he rehabbed with the Royals for all of 2022 rather than losing him to another team on a one-year deal. Brentz also would have been arbitration-eligible for the first time after this season, so this deal buys out one year but still gives the club two years of control.

The Royals can start building out their bullpen with Brentz in 2024, given that Amir Garrett and Aroldis Chapman are free agents after this year and Scott Barlow is a free agent after the ’24 season.

Brentz, who regularly sat 95-100 mph with his fastball, has a nasty slider that batters hit .191 off of in 2021, and he also incorporates a solid changeup at times. He brings closer potential to the Royals’ bullpen if he’s able to return to form after surgery. Brentz spent the offseason in St. Louis rehabbing with SSM Health and working out at All-Star Performance, honing his delivery and watching video -- all the things he can do to progress without throwing.

“I want to be a big piece of that bullpen, so that goes into my mindset every day and knowing that’s what I’m working toward,” Brentz said. “I want to come back as strong as I possibly can. … At the end of the day, I wanted to be here. I have a great agency, and we’re working with a great organization. I couldn’t be in a better spot.”

Brentz’s signing brings the Royals’ roster to a full 40 players, but he will likely go on the 60-day injured list once Kansas City needs a roster spot before Opening Day.