JUPITER, Fla. -- This spring, Isan Díaz aims to recover his Triple-A form in the midst of a battle to win Miami's second-base job. After recording an RBI extra-base hit for the second straight start in Monday afternoon's 7-7 tie with the Cardinals at Roger Dean Chevrolet Stadium, perhaps Díaz is inching closer.

In 2019, before his Major League callup, a then-23-year-old Díaz broke out, slashing .305/.395/.578 with a .973 OPS in 102 games at New Orleans. The former Top 100 prospect also put the ball in play more consistently, decreasing his strikeout rate from 29 percent in '18 to 22.1 percent in '19. But that hasn't carried over through 56 MLB games (29.6 percent).

After seeing 20 pitches across three at-bats on Sunday, Díaz wasted no time hacking away on Monday. He ambushed a first-pitch changeup from Cardinals prospect Junior Fernández, sending the ball to the right-field corner. Díaz wound up at third on the play, as two runners came around to score in a four-run first. On Sunday, he tripled to a similar location against Mets right-hander Marcus Stroman (104.9 mph exit velocity).

"As of right now, I'm just really focusing on trying to get the barrel on the ball," Díaz said during a Zoom call. "Obviously, that is two days in a row already down the right-field line, which is a good sign for me, because obviously those balls are fair. So it's a way of me saying I'm staying through that ball, keeping it fair. Anything else that would have been a fastball, anything deeper would obviously be more of a gap-to-gap kind of thing. But right now, it's trying to just put the barrel on the ball, trying to keep it simple, not really do too much and whatever happens, happens."

With another two runners on for his second at-bat on Monday, Díaz faced the tough task of St. Louis lefty Kwang Hyun Kim and struck out on three pitches. His day at the plate ended with a walk against right-handed reliever Daniel Ponce de Leon in the fifth.

Marlins manager Don Mattingly, who has seen a more comfortable Díaz the past two days, plans to rotate him and MLB Pipeline's No. 66 overall prospect Jazz Chisholm at second base this spring. One will start, while the other will come in after. They will take turns doing so.

"You can kind of tell with the takes, the swings," Mattingly said of Díaz during a Zoom call. "Just that he's seeing the ball good, and he's kind of on time. He looks good right now."

The latest on Sixto
Marlins top prospect Sixto Sánchez threw a "really good 'pen" on Sunday, according to Mattingly. The tentative next step is for him to pitch in live batting practice, and then go from there.

Sánchez, whose arrival to camp was delayed by visa issues, later was away from the club awaiting results following a false positive COVID-19 test. Asked how many Grapefruit League games Sánchez would need in order to make the Opening Day roster, Mattingly said five innings or 75-80 pitches to be built up for the regular season.

"With Six, we've always kind of rode that wave of making sure he's solid, and then move to the next step," Mattingly said. "We don't want to just schedule all the way out, and push him to our schedule. We want to make sure the schedule is fitting him and where he's at."

Hernandez's progress
Elieser Hernandez, projected as the rotation's No. 3 starter, continues to work on his changeup through two spring starts. It has been his third pitch since his MLB debut in 2018, but with decreased usage over the years (15 percent in '18, 11.4 percent in '19 and 6 percent in '20).

Hernandez turned to the changeup 11 times on Monday, recording two strikeouts with it, both swinging -- including one of All-Star slugger Paul Goldschmidt. Over 2 2/3 innings, the right-hander allowed a bases-clearing two-out double in the first. In his 44-pitch outing, Hernandez struck out four and walked one.

"Those were the pitches I was looking to use in that at-bat, and the best part of it [is] I got the result I wanted, and mostly with those batters," Hernandez said via an interpreter on a Zoom call. "I feel very happy for [the changeup]."

Off-day plans
Non-roster invitees Gio González and Jake Fishman will throw live batting practice on Tuesday. González, who signed a Minor League deal with the hometown club on Thursday, had his first bullpen session on Saturday. The southpaw provides veteran depth to the club's young starting staff. Fishman, a left-handed reliever with a 2.97 career ERA in the Minors, has not appeared in a Grapefruit League game.

Prospect watch
• Braxton Garrett (Marlins' No. 7 prospect) pitched two scoreless innings, allowing one hit and striking out two batters in his second spring outing.

• JJ Bleday (No. 20 overall) went 0-for-1 with a walk and a run scored.

• Chisholm finished 1-for-2 with an RBI single.

Worth noting
Infielder Demetrius Sims arrived at camp on Monday after passing COVID-19 intake testing. The Marlins' 14th-round Draft pick out of Bethune-Cookman University in 2017, he reached the Class A Advanced level in '19.

Up next
After an off-day on Tuesday, rotation candidate Trevor Rogers will make his second spring appearance in Miami's first night game of Grapefruit League play. First pitch is scheduled for 6:05 p.m. ET against the Astros at Roger Dean Chevrolet Stadium.