ST. LOUIS -- Hitless for the first time in his MLB career on Thursday, Cardinals budding star Jordan Walker had one thing on his mind as he went through a postgame weight room session designed to regenerate the energy in his lower body.

“It was cool, for sure, but it’s over now, and definitely it was a cool moment,” Walker said after an 0-for-4 performance ended his historic hitting streak at 12 games. “But now it’s time to start another one. That’s what I keep saying to myself.”

Walker, the 20-year-old elite prospect who made the Cardinals' Opening Day roster without ever playing in Triple-A, saw his hitting streak come to an end when the Cardinals lost 5-0 to the Pirates at Busch Stadium on Thursday.

Stuck at 0-for-3 coming into the ninth inning, Walker struck out looking in his final at-bat. Twice previously this season, the 6-foot-6, 245-pound rookie had notched hits in his final at-bat to keep the streak alive. It wasn’t to be on a night when he admitted struggling to pick up pitches out of the hand of Pirates starter Vince Velasquez, who limited the Cardinals to three hits over six innings.

In recent days, Walker set a Cardinals record for consecutive games with a hit to start his career, passed a mark set by Hall of Famer Ted Williams in 1939 and then equaled Eddie Murphy’s 111-year-old record for hits in 12 straight games by a player 20 years of age or younger. Ultimately, Walker’s streak to start an MLB career finished five games shy of the NL mark of 17 set in 1941 by Chuck Aleno and matched in 2016 by Colorado’s David Dahl.

“It’s super cool what happened, and now that it’s over I guess I can think about it a little more -- not that I want to,” joked Walker, who exited Thursday still hitting .294. “Days like this are going to happen. You can’t get a hit every game. But, it’s definitely been really cool to start with this streak.”

Walker struck out on three pitches in Thursday’s second inning. Then, after popping out in the fifth inning, he shattered his bat on an infield groundout in the seventh inning. His strikeout in the ninth inning was his 13th of the season.

Cardinals manager Oliver Marmol had nothing but praise for how the mature-beyond-his-years rookie has handled the transition to big league baseball and how he’s battled against pitchers challenging him with heavy doses of off-speed pitches. Also, Marmol marveled at the way Walker dealt with the pressures of a streak that gained national attention and one that might have made a lot of young players crumble.

“He’s done a nice job and he's played every one [of the Cardinals' 13 games]; when you're going through a streak like that, the last thing you want to do is give the guy a day off,” said Marmol, who hinted that Walker might get his first rest on Friday. “He did a nice job of handling everything that came with his debut and carrying it on to today. He should be proud of what he accomplished.”

Cardinals starting pitcher Jordan Montgomery, who allowed two runs over 6 1/3 innings on Thursday, said of Walker: “He’s 20 years old. Back then, I was in college and clueless. He’s super talented, a great guy and we’re happy to have him here.”

Walker came into Thursday hitting .319 with two home runs, eight RBIs and 19 hard-hit balls (95-plus mph) -- more than MLB superstars Aaron Judge, Mike Trout, Julio Rodríguez and Shohei Ohtani. During the first 12 games of his MLB career, Walker hit .333 at home and .304 on the road. Also, he had hit .313 when the Cardinals were ahead and .391 when they were trailing before Thursday.

The first-round pick of the Cardinals in 2020 said it would have been hard to imagine his MLB career getting off to a better start. He said he knew after a strong Spring Training performance he could play at this level. Thursday’s struggles -- or any others down the line -- will do nothing to break that confidence, he stressed.

 “After Spring Training, I felt I was ready for the big leagues,” Walker said. “I know that it’s not always going to be a great day at this level, but I still feel confident in my abilities no matter what happens the day before or the past week. I know that you still have to feel confident in this game.”