Greenberg booked a flight to Nashville and introduced himself to Orioles manager Buck Showalter. Later, he met special assistant Brady Anderson and passed along a message.
"I told him I'm a ballplayer and I wanted to play," Greenberg said.
The Orioles will give him another chance.
"They started talking to Alex Gonzalez, who's now my agent, and that's where it started. It kind of evolved from there," Greenberg said.
"When we went to the meetings, there were certainly other teams we were speaking to and there was definitely interest, but when the Orioles came back and said they wanted to give me an opportunity, that was everything because it was a legitimate opportunity to come to camp and try to earn a spot, and that was really all I wanted to hear."
The contract doesn't come with an invitation to spring training, but in Greenberg's professional baseball life - which includes a beaning on the first major league pitch thrown to him in 2005 and a badly torn rotator cuff four year later - it's a minor hurdle to clear.
"I don't usually get involved in those types of details," he said. "I just go about putting a uniform on me. Let me go out on the field. And I know what I can bring on the field. If I'm in minor league camp, I know they will bring me over. That's kind of been my MO since 2003 in my first spring training. Go over to big league camp and try to impress the staff. That's my thought process."
Before getting his one at-bat with the Marlins on Oct. 2, Greenberg played for Team Israel in the World Baseball Classic and spent three seasons with the independent Bridgeport Bluefish in 2009-11.
"I know it sounds bad to say I played independent ball for three years, but in 2009 I dived for a ball and tore my rotator cuff in my non-throwing shoulder, 90 percent through. But I stole 53 bases and did what I could on the field, and ultimately I had surgery - 2010 was my rehab year," he said.
"At this point in my life, I'm 100 percent dedicated to a success business that I'm running and I get to play baseball, and this opportunity with Baltimore, I'm going to prove them right for giving me this shot."
Greenberg is referring to a nutrition business called "Lurong Living," which you can read about here.
"I've always been involved in health and wellness, taking care of my body," he said. "I kid about how I'm 31 going on 22. I turned it into an opportunity to help others. It's legitimately impacted and changed my life. I can help others and it's allowing me to play baseball.
"I never played for money and I said I never wanted to retire for money. I didn't want finances to dictate it. I'm a ballplayer. I go out and play, and I'm really looking forward to doing that with the Orioles."