Apr 19, 2023; St. Louis, Missouri, USA; St. Louis Cardinals right fielder Jordan Walker (18) is congratulated by teammates after scoring against the Arizona Diamondbacks during the fifth inning at Busch Stadium. Mandatory Credit: Jeff Curry-USA TODAY Sports

Baseball's top prospect is back in the majors.

The St. Louis Cardinals recalled outfielder Jordan Walker, the top-ranked player on MLB Pipeline's top 100 prospects list, from Triple-A Memphis before Friday night's series opener against the Pittsburgh Pirates. Outfielder Lars Nootbaar was placed on the 10-day injured list, retroactive to May 30, with a lower back contusion.

Walker, who turned 21 on May 22, made the Cards' Opening Day roster out of spring training and posted a .274/.321/.397 slash line with two homers and 11 RBIs over 20 major league games. He began his career on a 12-game hitting streak — the longest streak to start a career by a player under 21 years old since Eddie Murphy had a 12-game streak in 1912. But with a glut of outfielders and the front office concerned about his launch angle and high ground ball rate, Walker was optioned to Memphis on April 26.

Walker struggled mightily after reporting to Triple-A, but he heated up in recent days and leaves the minors with a .239/.348/.398 Triple-A slash line this season.

This is the second IL stint of the season for the 25-year-old Nootbaar, who is batting .266/.380/.390 with four homers. With Nootbaar joining Dylan Carlson and Tyler O'Neill on the injured list, Tommy Edman and Óscar Mercado will seemingly soak up the reps in center field for the time being.