Eventually, Polanco likely will need surgery to repair the hernia, but he hopes to put that off until after the season because it's uncertain whether he would be able to return. Amaro said it took Raul Ibanez more than a month to recover from sports-hernia surgery after the 2009 season.
"It may not take just four weeks," Amaro said. "It took much longer than that on Raul. I don't think his issues are as severe as Raul's. There's no guarantee. We could say four weeks, but it may take a lot longer. Right now, we'd rather do this - not at the risk of injuring him any further - but we'd rather take this route and see if he can work himself through the season and then deal with it after the season."
Polanco, who had an MRI to determine the injury, said he is feeling better since the injection but needs a little more time to fully gauge its effectiveness.
Polanco was activated from the disabled list on July 29 after missing 31/2 weeks with lower-back inflammation resulting from a bulging disk. He played six games before he was sent home from the recent West Coast trip to undergo tests. The Phillies originally said he had soreness in his hip.
Phils sign Cust
With the hope of adding power to the bench, the Phillies signed Jack Cust to a minor-league contract. The 32-year-old outfielder was scheduled to report to triple-A Lehigh Valley on Friday night.
Cust, who is from Flemington, N.J., was released by Seattle on Aug. 4 after batting .213 with three home runs and 23 RBIs in 67 games.
The lefthanded hitter had 84 home runs and drove in 229 runs during a three-year period with Oakland from 2007 to '09. He has spent most of his career as a designated hitter.