A naked man who was shot in the back showed up at the home of Cal Ripken and pleaded for help, police said.
The retired Baltimore Oriole shortstop said he called 911, though police did not identify him by name.
"The homeowner called and said there was a man banging on his door and he didn't know what was going on," Baltimore County police spokesman Shawn Vinson said. "He called back a short time later and said the victim appeared to have been shot."
The wounded man, Brian Robins, 20, of Baltimore, was found on Ripken's porch Thursday night. He was treated at a hospital and released Friday, officials said.
Robins told police that he had been kidnapped Thanksgiving Day by three men who held him captive for nine hours, forced him into the trunk of their car, then ordered him to strip and run, Vinson said.
Robins said he was shot as he ran away, according to police.
Police are investigating the report and have not yet made any arrests.
"This was obviously an unusual and upsetting situation for me and my family, but I did what any other person would do given the circumstances," Ripken said in a statement. "I called the police, and they responded immediately and it is now in their hands."