PORT ST. LUCIE, Fla. -- Jordan Walker, the 20-year-old, elite-level outfield prospect who became the talk of the Grapefruit League with an early power surge and invoked memories of a young Albert Pujols from 22 years earlier, is headed to St. Louis and Major League Baseball.

The 6-foot-5, 220-pound Walker was informed on Saturday afternoon that he had made the Cardinals' Opening Day roster and would be added to the team’s 40-man roster. Later Saturday, the club announced its expected 26-man Opening Day roster, including Walker, who will be a fixture on a Cardinals team that has designs on winning a 12th World Series crown this season.

• Can Jordan Walker possibly be this good already?

"As of right now, Jordan Walker will make our club," president of baseball operations John Mozeliak said. "We were always very high on him coming into camp and he did a lot of things to impress a lot of people. He’s obviously a very mature player and has a great understanding of the game. He opened up a lot of eyes here in this camp, and he is someone who benefited from other people not being here [due to the World Baseball Classic].

"It created a lot of at-bats and innings for him, and he made the most of it."

Walker, ranked by MLB Pipeline as MLB's No. 4 prospect and No. 1 in the Cardinals' system, will make the jump to the big leagues without ever playing Triple-A baseball for the organization -- a feat similar to what Pujols did in 2001, when he was just 21 years old and slugged his way onto the roster. Similarly, Walker came to camp with all eyes on him and high expectations, and he still managed to outperform them.

In 19 Spring Training games, Walker went 18-for-63 (.286) with five doubles, three home runs and nine RBIs. His OPS was at a robust .816 following Saturday afternoon’s 3-2 loss to the Marlins. Walker’s strikeouts (14) soared late in camp, but he did draw his second walk of the spring on Saturday.

"Before I told him, I asked him what his best tool was and what was the greatest thing he brings to the table," manager Oliver Marmol said. "I was curious if he would say something along the lines of, 'My bat' or something like that, and he said, 'I don’t think about things very long; good or bad, I just kind of move on to the next thing.'

"That affirmed why he’s ready," Marmol said. "That’s the separator. To get to the big leagues, yes, you've got to be able to hit, but when things get tough and you face adversity and people start to question your ability, can you cancel out the noise and keep doing your job? I think he has that ability."

Now, Walker, a first-round pick (21st overall) from the 2020 MLB Draft, is expected to be in the starting lineup on Thursday afternoon when the Cardinals host the Blue Jays at Busch Stadium. Marmol and Mozeliak have said repeatedly throughout Spring Training that if Walker made the roster, it would be as a starter. A third baseman early last season when he starred at Double-A Springfield, Walker made a successful conversion to the outfield, and he can play either corner-outfield spot. Designated hitter is also a possibility for Walker, who smashed home runs of 470, 450 and 430 feet during Spring Training.

Earlier this week, Walker said through a wide grin that an MLB nod would likely send his emotions soaring. A former Gatorade Player of the Year while in high school in Georgia, Walker rose quickly through the Minor Leagues and now is about to accomplish a childhood dream. He informed his father, mother and older brother simultaneously of the news on Saturday via a family FaceTime -- even though his dad, Derek, was sitting next to him in his apartment. 

"We were all ecstatic," said Derek Walker, who noted that the family will have at least 15 supporters at Busch Stadium on Thursday. "We had been holding our breaths in the last week because the results have been less than stellar. We didn't know if that would affect anything, but we're happy that the Cardinals felt he showed enough early on in camp when he excelled."

Seven times in their history, the Cardinals have rostered a player 20 years old or younger on Opening Day, including Hall of Famers Steve Carlton (20 years, 11 days) and Rogers Hornsby (19 years, 351 days and 20 years, 349 days). The most recent Cardinal to debut at the MLB level before turning 21 was Rick Ankiel in 1999. Coonie Blank was the youngest player to wear a Cardinals uniform, doing so in 1909 when he was just 16 years and 301 days old.

Walker's closest friend on the Cardinals, fellow 2020 draftee Masyn Winn, said he let out a loud roar on the team bus to Port St. Lucie when Walker texted him that he had made the Opening Day roster.

"He texted me, and I think the whole bus knew the second I knew because I jumped up and down, cussing and punching the seat," said Winn, who had two hits, a walk and a spectacular diving-stop double play in the Cardinals' 4-4 tie versus the Mets on Saturday. "I'm just so happy for him. I almost shed a tear for him. He’s 20 years old and about to go and do this thing. He's going to go and ball out this year, for sure."

Walker rose above expectations not long after he showed up at Spring Training as a non-roster invitee who was promised every opportunity to show off his five-tool arsenal. By March 10, he was leading the Grapefruit League in batting average (.452), slugging (.839), OPS (1.291), total bases (26) and hits (14), and he was tied for first in extra-base hits (six). 

As is often the case for young players in baseball, Walker was unable to maintain his torrid start to Spring Training and cooled off later in camp. After injuring his shoulder in West Palm Beach on March 11, Walker had four hits in his next 30 at-bats with nine strikeouts and just two extra-base hits.

Still, Marmol said on Saturday that Walker greatly impressed the club with his maturity, baseball IQ and willingness to learn from those around him.

"We can talk about tools all day, but those don't play if you can't handle some pressure," Marmol said. "This is not the degree of the pressure that he'll experience at the big league level, but it's still an example of the most [pressure] he's had to [deal with] around the big league club. So, you're just keeping an eye on that and seeing how he responds, and I feel like he did that well."