St. Louis optioned first baseman Matt Adams and outfielder Adron Chambers to Triple-A Memphis.
Carpenter played in his sixth rehab game on Thursday, a day after he played a full nine innings in right field. He had four hits in 17 Minor League at-bats, and the right oblique strain that sidelined him was not an issue.
Jay began his rehab assignment later than Carpenter, but manager Mike Matheny had noted that Jay's early results could speed up the center fielder's timetable. Jay, who was on the DL because of a right shoulder sprain, had three hits -- including a triple and a home run -- in seven Triple-A at-bats.
Jay's return will mean more playing time at first base for Allen Craig. With Carpenter also able to play that position, at-bats would have become sparse for Adams. As for Chambers, he falls further on the center-field depth chart.