Hanrahan blew two consecutive save opportunities on Friday and Saturday against the Marlins, who won both games.
"We have a closer," Acta said. "He had a couple of rough days. They could have come later in the year, he just had them back to back. You just have to hope for the best. ... We like this guy. We are going to give him a chance."
In five games this season, Hanrahan has given up five runs in five innings, but he makes no excuses.
"I have to pitch better. That's all it is. I'm not hitting my spots," Hanrahan said.
If Hanrahan continues to struggle, look for Acta to go to with either Joe Beimel or Garrett Mock in the closer role.
Beimel has given up one run in 6 1/3 innings, and Mock, who was recalled on Monday, was groomed to be the closer while at Triple-A Syracuse. He earned two saves in five relief appearances in the Minor Leagues this year.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.