ST. LOUIS - The Phillies have not determined how many games Domonic Brown will spend in triple A before he is recalled. Manager Ryne Sandberg said the length of Brown's stay with Lehigh Valley will hinge on when the rightfielder shows he's ready to help the major-league club.

"It's really for his benefit," Sandberg said, "to really work on some things and to get right."

Brown, 27, was optioned to triple A on Tuesday upon his activation from the 15-day disabled list. He had spent the last week and a half with the IronPigs on a rehab assignment but struggled at the plate. A minor-league option remaining on Brown's contract offered the Phillies flexibility.

As of Tuesday afternoon, Brown had yet to report to Coca Cola Park in Allentown. Players are afforded 72 hours to report to minor-league destinations. Brown, although already in town, was still granted that window because while he rehabbed the tendinitis in his left Achilles he was not technically on the triple-A roster.

In nine rehab games with the IronPigs, Brown managed just five hits in 36 at-bats (.139). He was 5 for 17 in six games with single-A Clearwater at the start of his assignment.

Except for rehab stints, Brown has not been a minor-leaguer since the first half of the 2012 season, before the Phillies traded outfielders Shane Victorino and Hunter Pence that July. Brown was an all-star in 2013 but regressed last season into statistically one of the worst everyday players in baseball.

After trading Marlon Byrd in December, the Phillies shifted Brown from left field back to his more natural position in right. The former top prospect worked this spring with Mike Schmidt to cut down on his sometimes loopy swing. He exited a March 19 Grapefruit League game with the injury.

"We have to get him ready for the big leagues. Bottom line, that's what we're here for," Lehigh Valley manager Dave Brundage said. "Bottom line for him is we have to get him to where his timing needs to be so he can help our major-league club. . . . I'm sure the big-league club didn't think he was ready yet and that's why he's going to be here."

Extra bases

Centerfielder Odubel Herrera entered Tuesday night's game leading National League rookies in batting average (.300), hits (21), doubles (5), and triples (2). . . . The Cardinals announced that lefthander Tim Cooney will come up from triple A to start the series finale Thursday against the Phillies in place of the injured Adam Wainwright. Cooney, 24, hails from Collegeville and graduated from Malvern Prep.

- Jake Kaplan and Matt Breen