MIAMI -- Marlins rookie infielder Jazz Chisholm Jr., eligible to return from the injured list on Saturday, continues to progress from a left hamstring strain, manager Don Mattingly said on Thursday. Chisholm, who has been sidelined since April 28, was cleared to run on Wednesday. He also took ground balls and hit.

"He has started that progression, and then it's just a matter of us listening to medical of how that progression goes," Mattingly said. "It's probably day to day, kind of the same with Jorge [Alfaro]. It was kind of the same with [Brian Anderson] as he started moving. We'll listen to their body. What's going on the next day, can you progress or do we have to slow down just a little bit or leave it the same until we move forward again? Haven't heard if he came in feeling good today or not, but I know he's scheduled to continue that progression."

Anderson (left oblique strain) was activated from the IL one game after he was eligible. Alfaro, who is doing agility work and catching drills, had previously missed four games (April 7-12) with left hamstring tightness as the club monitored his discomfort day to day. The catcher returned for a week of games before straining the hamstring and landing on the IL on April 21.

Prior to his injury, the 23-year-old Chisholm slashed .290/.375/.551 with a .926 OPS in 21 games, which garnered him National League Rookie of the Month votes. He strained the hamstring while stealing his seventh base in the first inning of a 5-4 loss to the Brewers on April 27.

Isan Díaz, who lost out on the second-base job during Spring Training, has started in Chisholm's place. In six games, he is 3-for-18 with two runs, one homer, four RBIs, five walks and four strikeouts. With southpaw Madison Bumgarner on the mound Thursday, Jon Berti got the nod at second instead of the left-handed-hitting Díaz.

Lord of the rings

Reliever John Curtiss, whom the Marlins acquired from the Rays on the day pitchers and catchers reported for Spring Training, recently received his American League championship ring. He was part of Tampa Bay's 2020 roster, compiling a 1.80 ERA in 17 regular-season outings. The righty appeared nine times in the playoffs, with one start and three games finished.

"It was very cool. I want to get an NL one. I'd love to get another one that says 'World Champions' instead of 'American League' or 'National League,'" Curtiss said. "But certainly, that was an unbelievable experience, super grateful for everything the Rays did for me and for quite frankly resurrecting my career. I was out of baseball for eight months, and they were the only team that offered me a Minor League contract. Always got a special place in my heart for them, but honestly, looking at that ring -- as cool as it was -- just made me want another one. So that's kind of greedy."

Top prospects roundup

Triple-A Jacksonville

• OF Monte Harrison (No. 14), who was optioned on Tuesday, hit a solo homer.

• OF Jesús Sánchez (No. 6) went 2-for-3 with a walk.

Double-A Pensacola (Game 1 of a doubleheader)

• LHP Jake Eder (No. 24) struck out 12 over five scoreless innings in his professional debut. He allowed one hit and walked three.

• OF Peyton Burdick (No. 12) hit a two-run homer and walked.

• OF Jerar Encarnación (No. 21) went 2-for-2 with two walks and an RBI double.

High-A Beloit

• OF Connor Scott (No. 16) went 3-for-5, falling a double shy of the cycle.

• RHP Kyle Nicolas (No. 17) allowed one run on one hit with four walks and eight strikeouts over five innings in his professional debut.