PEORIA, Ariz. -- He’s 27 now, one of the “old guys” on a Mariners team filled with promising prospects. But this is right where Taijuan Walker wants to be, back with the club where he once was one of the most-promising prospects himself.

After signing a one-year, $2 million free-agent deal with Seattle on Wednesday, Walker took to the field Thursday with 33 other hurlers for the first day of pitchers and catchers workouts at the Peoria Sports Complex.

It’s been four springs since Walker last practiced in Peoria, before he was traded to the D-backs by general manager Jerry Dipoto in a move that brought Mitch Haniger and Jean Segura to Seattle. The only Major League teammate remaining from his last turn with the Mariners is Kyle Seager.

But baseball has a way of coming full circle, and the big right-hander finds himself again with the club that drafted him as a 17-year-old out of Yucaipa High in California and got him started on his Major League career with four seasons in Seattle.

“I’ve come back,” Walker said after his first workout, “and it feels good.”

Most importantly, at this point, his right arm also feels good. Walker has pitched just four innings over the past two seasons after Tommy John surgery in 2018 and shoulder issues last season. The Mariners will bring him along slowly this spring, with the hope of having him ready to fill a full-time rotation role once the real games begin in six weeks.

Walker threw off the mound in four bullpen sessions prior to camp. He’s slated to throw again Saturday.

“We’re not going to just go pedal to the metal and run him out there as fast as we can,” manager Scott Servais said. “But he’s ready to go. We’ll build him up, get him stretched out. I’m excited to have him back, and he’s happy to be back.”

Walker acknowledges he’s a different pitcher and person now than the 23-year-old who was traded in 2016. He went 9-9 with a career-best 3.49 ERA in 28 starts for Arizona in ’17 before the health issues cropped up. And that successful year opened his eyes.

“I definitely had a lot of stuff to learn,” he said. “I don’t think I did a very good job here, doing what I need to do to be the best pitcher I could be. I definitely slacked off and didn’t really put the work in. When I went [to Arizona], there was opportunity, and it was fresh faces for me.

“We had good veterans that kept on me the whole time, and I just learned a lot and learned how to be a good pitcher. Having Zack Greinke over there and a bunch of guys who were hungry and ready to work, I just fell in line with them.”

Walker hopes to be one of those leaders now upon his reunion with the youthful Mariners, who have just six pitchers out of the 35 in camp who are older than him.

Notes from camp

• While most of the position players are already in camp prior to Monday’s report day for the rest of the squad, Haniger, an outfielder, has yet to check in as he recovers from recent sports hernia surgery. According to a report from ESPN's Jeff Passan, Haniger underwent another surgery on Thursday, his second in three weeks, which will further delay the start to his 2020 season.

“There’s still no timetable on Mitch,” Servais said. “I know he’s frustrated with everything he went through last year. He’ll work his tail off, and we’ll get him back as soon as we can.”

• Reliever Austin Adams isn’t running yet as he rehabs from surgery to repair a torn ligament in his left knee, but the 28-year-old right-hander has begun throwing -- albeit without putting any weight on his front leg -- and has been working on improving the spin efficiency on his fastball.

“Instead of just sitting there, I kept the arm in shape and hopefully it pays dividends,” Adams said. “Hopefully I can start playing catch soon. I feel awesome and had a really good offseason. I’m excited to be back here."

Adams doesn’t have a date in mind for when he might return to the mound, but knows it’ll be at least two months since he was placed on the 60-day disabled list Wednesday to open a 40-man roster spot for Walker.

The 60-day DL clock doesn’t start until the first day of the regular season on March 26, so Adams won’t be eligible to return until at least May 26. Odds are it’ll be more toward mid-June or later before he’s cleared to go.

• Seattle’s young outfielders will have plenty of help on the coaching front this spring, as former Mariner Franklin Gutierrez will spend about a month in camp working with players, while Ichiro Suzuki and Mike Cameron have also returned as part of the invited staff. National Baseball Hall of Famer Edgar Martinez and Mariners Hall of Famers Dan Wilson and Alvin Davis will also be assisting all spring.