JUPITER, Fla. -- A Cardinals club that was aggressive in the offseason to acquire proven and reliable pitching that they hoped would bring much-needed stability to their staff will have to open the 2024 season without injured ace Sonny Gray.

What has looked likely since Gray suffered a strain to his right hamstring on March 4 became official on Sunday when manager Oliver Marmol announced that veteran right-hander Miles Mikolas -- and not the injured Gray -- will pitch the Cardinals' opener against the Dodgers on March 28. Gray, who signed a three-year, $75 million free-agent contract in November, was named the Opening Day starter three weeks ago, but that designation was removed on Sunday when the Cardinals decided to push his debut further into the season.

Gray, 34, threw his third bullpen session off a bullpen mound on Sunday and he will do so again on Thursday -- likely against live hitters for the first time since suffering the injury. If all goes well, Gray could possibly make a Spring Training start on March 25 or 26 in Arizona against the Cubs, which would potentially set him up for his 2024 debut against the Padres in San Diego (April 1-3).

“I won't [speculate on] when it’s possible for him to throw … in the home opener or pitch in San Diego; I think the smartest thing is just to see how he comes out of this [Sunday bullpen] and then in the next one how he responds,” Marmol told reporters on Sunday.

“I'm relying more on him and trusting him through this process,” Marmol added. “He understands his body really well, he’s been around, and he knows what he needs in order to pitch in a big league game. So, I’ll rely on his words.”

Mikolas, 35, has been the Cardinals’ most consistent starter throughout the spring, going 2-0 with a 2.25 ERA and 12 strikeouts in 16 innings over four starts thus far. Mikolas is trying to bounce back following a subpar season in 2023, when he led MLB in starts (35), but also in hits allowed (226). He’s 0-2 in his career as an Opening Day starter, allowing five earned runs in 2019 in Milwaukee and five runs last season at Busch Stadium in a start against the Blue Jays.

“I think I’ve had two Opening Days before -- not so great -- but I think the third time’s the charm,” Mikolas said. “That’s the game that you want and all those games in L.A. are going to be great. All the hoopla with all their additions, that’s why I play. I want the big games. In Los Angeles, I want to hear the boos and the roar of the crowd. It’s going to be an exciting atmosphere and I’m going to do my best to keep the butterflies and jitters at bay and do my job.”

On Saturday, Mikolas took some good-natured jabs at a Dodgers franchise that spent approximately $1.2 billion in the offseason while acquiring Shohei Ohtani, Yoshinobu Yamamoto and Tyler Glasnow -- something that should only add to the theater of Opening Day.

“We’re not exactly a low payroll team, but you got the Dodgers playing checkbook baseball,” Mikolas cracked. “We’re going to be the hardest working group of Midwestern farmers we can be. … It would be great to stick it to the Dodgers.”

The Cardinals signed veterans Lance Lynn, Kyle Gibson and Gray to stabilize a starting staff that struggled to get deep into games and often left the club in big early holes last season. They also worked to fortify the bullpen with the additions of Keynan Middleton, Andrew Kittredge, Riley O’Brien, Ryan Fernandez and Nick Robertson. However, the club suffered a blow on Saturday when it learned that Middleton will open the season on the injured list because of a right forearm strain.

Marmol feels that the Cardinals are better positioned this season to handle Gray and Middleton not being ready for the start of the season because of injuries.

“I do feel like we have better answers,” said Marmol, who signed a two-year contract extension with the Cardinals on Friday. “I feel better about what we have, and we're going to plug in guys and keep going. … We’re a guy down and we have to figure it out until [Gray] is back. It happens, you don't want it to happen early, but it's going to happen at some point.

“But we're starting off that way and thankfully, we feel good about our depth to be able to get to where we need to get to. We just need [Gray] to get healthy and rejoin us.”