SAN FRANCISCO – The St. Louis Cardinals have optioned rookie outfielder Jordan Walker to Triple-A Memphis, less than a month after his MLB debut.

Walker had been held out of the lineup in three of the past four games, and five times in the Cardinals’ last 11 games. Before that, he had started 13 consecutive contests and opened his MLB career on a historic 12-game hitting streak.

Though some rest always seemed inevitable on a crowded Cardinals roster, Walker’s absences from starting lineups have mounted in recent weeks.

The Cardinals, searching for answers to one of their slowest starts in nearly half a century, have shuffled lineups on a near-daily basis. St. Louis has also dropped its last four without the 20-year-old rookie in the starting lineup, leaving many fans wondering whether there’s something more behind the decision.

Cardinals manager Oli Marmol told several media members Tuesday, including MLB.com’s John Denton and The Athletic’s Katie Woo, that Walker has spent some time working with Cardinals’ hitting coach Turner Ward.

Walker is working with staff to adjust his posture and rotation, and the adjustment period likely factors some into his recent stretch of rest. The idea is to reduce grounders and chasing low pitches, which have become slightly more common since Walker’s hitting streak ended. The explanation would lead some to think that Walker’s absence from lineups has been more due to a learning curve, rather than performance-based or injury-related reasons.

Holding Walker out of lineups is a trend that might be difficult for the Cardinals to justify. The idea behind promoting a young talent, especially a former first-round prospect, is generally to pave the way for regular playing time. The Cardinals are scrambling to find consistent playing time for Tyler O’Neill, Dylan Carlson and Alec Burleson in the outfield too, making Walker’s situation a bit tricker.

Walker broke camp with the Cardinals out of spring training without experience at the Triple-A minor league level. At least in short order, an option to Memphis proved to help somewhat for young hitters Lars Nootbaar and Nolan Gorman last year into becoming more regulars this season.

The Cardinals are 9-15 nearly a month through the 2023 season and have lost six of their last eight games. The Cardinals are bringing back infielder Taylor Motter to the big-league roster, days after designating him for assignment.