Photo: Karen Warren, Staff Photographer Photo: Karen Warren, Staff Photographer Photo: Karen Warren, Staff Photographer Photo: Karen Warren, Staff Photographer Photo: Karen Warren, Staff Photographer

WEST PALM BEACH, Fla. — Yordan Alvarez wants to play outfield. Whether his knees will allow it remains one of the biggest mysteries of Astros camp, one deepened on Thursday with a surprising revelation.

Alvarez acknowledged on Thursday that pain predated the two foul tips off of his left knee during his last major league season. He played through pain “all season,” but could not specify an incident that caused it or diagnosis for it.

“I just worked hard every day to make sure I warmed up my lower body properly and just went out and played,” Alvarez said through an interpreter. “I tried to manage it as best I could that way.”

Whatever the regimen was worked. Alvarez struck a rookie-record 27 home runs, finished with a 1.067 OPS and unanimously won American League Rookie of the Year honors. He played the outfield just twice in the team’s final 41 games — including Game 5 of the World Series in Nationals Park.

On the awards circuit this winter, Alvarez was adamant he wanted to play more outfield. He worked all offseason on strengthening his lower-half and his routes in left field. He said Thursday that routine included “lower-body leg strength and agility work.”

“I feel good in the outfield,” Alvarez said. “I’m just preparing to play as much as I can out there and play it well.”

Still, Alvarez’s knees remain a question mark. Manager Dusty Baker’s already mentioned Alvarez’s knees were “barking” multiple times in camp. Alvarez played four innings of left field on Tuesday against the Marlins, but did not have a ball hit his way.

The dilemma Baker must confront is whether to test Alvarez’s already balky knees in the outfield, where a risk exists of further pain that could impact his offense.

“As of this moment, I feel good,” Alvarez said “I know that Dusty had said they’re barking a little bit, but for now I feel good. I don’t think it’s something that affected me from last year, I just think it’s something that I did have knee problems last year, but it’s something that I’m just watching this year a little bit.”

In an ideal world, Baker would honor Alvarez’s wishes. Baker sees the benefit in spreading around his designated hitter duties.

George Springer and Michael Brantley excelled last season in their limited exposure. Springer swatted six of his 39 homers as a DH. Brantley, injury-prone for some of his career, finished the season without any ailments and the second-most plate appearances of his nine-year career.

“A lot of it depends on Yordan,” Baker said Thursday. “That’s why we’d play him in the outfield, so I could spread it around.”

ASTROS INSIDER: Follow the Houston Chronicle’s spring training coverage as the Astros prepare for the 2020 season.