MIAMI — Seven years later, Adam Greenberg will get to step back in a major league batter’s box.

Greenberg, a North Carolina standout in the early 2000s, had his major league career end on the first pitch he saw, a 92-mph fastball that struck him in the head.

With the help of a filmmaker who created a campaign in February encouraging a major league team to give Greenberg another shot, his comeback attempt gained national attention.

The Miami Marlins on Thursday signed Greenberg to a one-day contract, and he will play Tuesday against the New York Mets.

“Life’s going to throw you curveballs – or fastballs in the back of your head,” Greenberg said on a conference call Thursday morning. “I got hit by one of them. And it knocked me down and I could have stayed there. I had a choice ... and I chose to get up and get back in the box.”

Matt Liston, a filmmaker from Santa Monica, Calif., knew about Greenberg because he is a Cubs fan, and his Chicago team was playing the Marlins in South Florida on July 9, 2005.

That’s when Greenberg’s life changed forever.

Liston wanted to help him make it right.

With the ESPN Sunday Night Baseball cameras rolling, Greenberg made his big-league debut with the Cubs as a pinch-hitter in the ninth inning. Facing left-hander Valerio De los Santos, the left-handed Greenberg, now 31, said he was determined to be aggressive and not bail out of the batter’s box.

“He threw me a 92-mph fastball, and I turned to try to avoid it,” Greenberg said. “It caught me square on the back of my helmet, right on my actual skull.”

Greenberg was sent back to the minors, where he was on the disabled list for the next 21 days. But he experienced vertigo and intense headaches for the next 18 months.

“Anytime I would tie my shoes or roll over in bed or move too quickly, I would get these migraines that would go on for hours,” said Greenberg, a former ACC Rookie of the Year at North Carolina and a ninth-round pick of the Cubs in 2002. “More than baseball, I was concerned about my quality of life.”

Greenberg continued to play. He even got a hit off De los Santos in an independent league game last year.

“That was sweet — probably the biggest hit of my career,” Greenberg said of the single.

A speedy 5-9, 180-pound outfielder, Greenberg said he hit his low point in 2007, when he was released by the Kansas City Royals’ organization despite hitting .266 with 30 doubles, 11 triples, eight home runs and an on-base percentage of .373 at Double A.

The last time he was affiliated with a major-league organization was in 2008, with the Los Angeles Angels. He played independent ball until 2011, before taking this year off to start a business.

He’s married now, after all. He and his wife, Lindsay, were grade-school classmates in Guilford, Conn., but they hadn’t seen each other in nine years when they met again in 2008. They wed in 2010.

“We didn’t need to get to know each other,” Lindsay said, “because we already knew each other.”

In February, Greenberg was contacted by Liston, who had recently watched “Field of Dreams” with his wife, Marisa. When she said she felt bad for “Moonlight” Graham, the real-life player who played in just one major-league game (1905) and never batted, Liston thought of Greenberg.

“Moonlight’s got nothing on Adam Greenberg,” he told his wife. “Moonlight played two innings in the field. Adam didn’t even get two seconds.”

Liston soon discovered that Greenberg was still playing.

With Greenberg’s permission, Liston created a website — www.oneatbat.com — and within a week had received 20,000 signatures for a petition to give Greenberg another shot in the majors.

“Once I saw that Adam was in better shape than most of the players in the majors and that he is still working out and committed, I made this my mission,” Liston said. “Adam can actually make a team. He can get on base, he can steal. He’s so fast in the outfield, it’s ridiculous.”

Liston contacted numerous general managers around the majors, hoping Greenberg could get another chance with the rosters expanded.

Before the Marlins signed Greenberg, Liston said Miami would be the perfect scenario, given that Greenberg was injured against the Marlins, and Miami and New York have large Jewish populations that would provide an extra hook to what he believes would be the “feel good story of the year.”

Liston said several players around the majors, including the Marlins’ Giancarlo Stanton, have told him they would gladly give up one of their at-bats for Greenberg.

“Are second chances only supposed to be given to players who fail drug tests?” Liston said. “Tell me Adam doesn’t deserve this chance.

“The outpouring of love and support that a team would get for playing Adam would be amazing. And I don’t think the story would end there. I think the team that gives him a chance will see his value on the field.”

Information from the Associated Press was used in this report.