ST. LOUIS -- After making his Major League debut last season and following up with a small but impressive sample at Spring Training, Cardinals reliever Junior Fernández is ready for what the 2020 season will bring.

The nearly four-month wait has been long -- and extended slightly because of testing delays that kept him off the field until earlier this week -- but it’s finally here. Now, Fernández is showing the Cardinals what he’s done to improve over the time off. He threw two times per week in Jupiter, Fla., and worked out with Yadier Molina -- not a bad catcher to have on your side.

“The way that Yadi approaches the game is amazing,” said Fernández, ranked by MLB Pipeline as the Cardinals' No. 10 prospect. “He’s always concentrated, always trying to get me to be better, see what I do wrong while pitching, if I move my glove, all that. He’s always trying to help everybody. I can’t explain everything. Yadi is an amazing person, an amazing teammate.

“In my mind, I was always thinking that the time is coming, any day is going to be that call for me. Working down there with Yadi got me ready, and now I’m here to show them that I was ready for it, waiting for it. All that time lost -- I never lost it. I kept training, and now I’m here.”

Fernández could play a part in the Cardinals' bullpen, especially to start the season with a 30-man roster and three relievers -- Giovanny Gallegos, Alex Reyes and Génesis Cabrera -- not yet cleared to work out at Busch Stadium. Fernández, a hard-throwing righty, could pitch his way to a high-leverage role with St. Louis. In 13 appearances with the Cardinals last season, the 23-year-old struck out 16 in 11 2/3 innings and compiled a 1.52 ERA with 80 strikeouts in 65 Minor League innings.

With a little more fine-tuning in the Majors, Fernández has the pure stuff -- a plus sinker, a biting slider and an above-average changeup -- to be effective in a high-leverage reliever role.

“What I appreciated about Junior was he wanted to pitch,” manager Mike Shildt said. “He came up near the end of the year, we’re in a pennant race, and this guy wanted the ball. And we gave it to him in big situations.”

Miller day to day
Veteran infielder/outfielder Brad Miller is day to day with heel discomfort, Shildt said Friday. The injury kept Miller out of the lineup during Thursday’s intrasquad matchup and off the field for live batting practice Friday.

“He will be somewhat limited maybe tomorrow, and we’ll evaluate as we go, but it’s not anything that we need to push or he needs to push through,” Shildt said. “It’s not anything that we or he thinks is overly serious and requires any real time missed other than a couple days.”

‘A great science fair experiment’
It’s not all the time Major League pitchers can face their own teammates and get feedback so close to the season, but with Summer Camp at Busch Stadium and only intrasquad games to get ready for Opening Day, that’s what Cardinals pitchers are doing. For Adam Wainwright, it’s allowing himself to experiment with the adjustments he made during the time off.

“As you get older, [it’s a] game of adjustments,” Wainwright said after throwing five innings of live batting practice Friday. “I’m working on just seeing -- these hitters are going to tell me what works and what doesn’t. So this is a great science fair experiment.”

Wainwright explained how, after his 75-pitch outing, he was able to get feedback from second baseman Kolten Wong about what his pitches looked like and the experience facing Wainwright. It made the veteran starter want to go back out to the mound right then. Wainwright said his arm is “in a good spot,” and when asked if a shortened, 60-game season like 2020 could extend his career, he didn’t discount the idea.

“Well, it could,” Wainwright said. “You never know. I’m literally only thinking pitch to pitch, trying to stay in the here and now. But you never know, man. It’s a funny thing how things work out sometimes. I don’t know, we’ll see. I’m feeling pretty confident though.”

Around the horn
• In live batting practice Friday off lefty Kwang Hyun Kim, Matt Carpenter lasered a line drive to the left-center-field gap, bound for the warning track. But before it dropped, top prospect Dylan Carlson, playing center field, ran it down and snagged it over his shoulder. Paul Goldschmidt followed with a homer off Kim, and the ball clanged into the right-center-field bleachers, echoing through an empty stadium.

• Donning blue surgical gloves, Johan Oviedo was on rosin bag duty for Friday’s live batting practice sessions. The Cardinals’ 11th-ranked prospect was tasked with throwing each pitcher their individual rosin bag when they came to the field in an effort to limit contact. Oviedo will start Saturday’s intrasquad game.

• Along with Oviedo, Carlos Martínez will start Saturday’s three-inning intrasquad matchup. Kodi Whitley and Tyler Webb are scheduled to pitch an inning in relief.

• Dexter Fowler did not appear on the field at workouts Friday.