MIAMI (AP) -- Adam Greenberg has faced one pitch in the major leagues, a 92 mph fastball that struck him in the head and changed his life.
More than seven years later, the Miami Marlins are giving him a second chance.
The Marlins said Thursday that they have signed Greenberg to a one-day contract, effective Oct. 2, and will play him that day against the New York Mets. Greenberg made his big league debut for the Chicago Cubs on July 9, 2005 against the Marlins, getting one plate appearance but no official at-bat.
''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.''
The Marlins publicly extended the invitation to Greenberg on NBC's ''Today'' show Thursday morning. Greenberg, however, said team president David Samson called him Sunday night to actually tell him of the team's plans to sign him to a one-day deal.
''I'm extremely proud to extend this opportunity to Adam,'' Marlins owner Jeffrey Loria said in a statement.
Marlins manager Ozzie Guillen said Greenberg may start.
''I might start him in left field and have him lead off,'' Guillen said before Thursday night's game in Atlanta. ''If he hits a home run, he stays!''
Greenberg, a left-handed batter, went to the plate as a pinch hitter to face the Marlins' Valerio De Los Santos with one out in the ninth inning of the Cubs-Marlins game. De Los Santos' first pitch sailed up and in, striking Greenberg in the back of the helmet, the force being such that the helmet flew off and the ball ricocheted up the third base line.
Greenberg tumbled to the dirt, both hands holding the back of his head. He has often described that moment as feeling like ''my head exploded.'' He awoke the next morning with symptoms of a concussion - unable to focus and feeling nauseated when seeing bright light.
After struggles in the minors the next season, the Cubs released him in June 2006. Greenberg had chances with other minor league teams, but never made the majors again.
''They're trying to give this kid a dream come true,'' Guillen said. ''Why not give the kid a chance to be what he wants to be?''
Guillen said he has had a couple days to consider the best way to use Greenberg. He thinks it will be better to have Greenberg start than to find the right place in the game to come in as a pinch hitter.
''It's more important to me to win the game,'' Guillen said.
Marlins right-hander Carlos Zambrano was with the Cubs in 2005 and was used as a pinch runner for Greenberg. Zambrano said Thursday he did not remember his role in the game.
''He wasn't a fit for us,'' Cubs manager Dale Sveum said Thursday. ''I wish him the best.''
The Mets' probable starter on Tuesday will be Cy Young candidate R.A. Dickey.
''I know our guys will be on the top step clapping for him when he gets in the batter's box,'' Mets manager Terry Collins said Thursday when asked about Greenberg's story.
Greenberg is one of only two players in baseball history to be hit by a pitch in his first-and-only major league appearance and never take the field. Fred van Dusen endured that fate with Philadelphia in 1955.
Greenberg was the subject of a campaign called ''One At Bat,'' which lobbied teams to give him a second chance - since his first appearance in the majors did not count as an official at-bat, just merely a plate appearance.
''I just really want to make sure everyone understands that this is an amazing thing, for not just me but for a lot of people,'' Greenberg said.
He and Marlins outfielder Justin Ruggiano once were teammates with the Double-A Jacksonville Suns, playing together there in 2006.
''Dude can play,'' Ruggiano said on Twitter.
It is ironic how the Marlins have been involved in just about every aspect of Greenberg's story.
His lone plate appearance for the Cubs came in Miami. When he played earlier this month for Israel's entry in the qualifying round for the World Baseball Classic, he played and trained at the Marlins' complex in Jupiter, Fla. And now his comeback game will be in Miami, albeit a different park than where he faced that fateful pitch seven years ago.
''Going back to the scene of the crime but a different location, I kind of look at it as a new stadium, new start,'' said Greenberg, who drew a walk in his lone plate appearance for Israel in the WBC qualifying games. ''For me, it's just down the street, but it's a new opportunity. It's really cool and special to have the Marlins, of course, recognize all of this. And to have it come full circle with them, it's just so gratifying, rewarding and special.''
Greenberg faced De Los Santos again in 2011, hitting a single off him as a member of the Bridgeport Bluefish in the independent Atlantic League.
The Marlins say Greenberg will donate his one-day salary - a pro-rated share of the minimum contract is $2,623 - to the team's foundation, which will in turn donate to the Sports Legacy Institute, a group that furthers the study, treatment and prevention of the effects of brain trauma in athletes and others.
Greenberg said he's hopeful of getting a chance to play for some club in spring training next year. He also insisted that this is not a stunt.
''I'm no different or more special than anyone else,'' Greenberg said. ''It just so happened that my story was the Sunday Night Baseball game on ESPN and it was the first pitch I ever saw and I got hit in the back of the head. Tragedy for me, but it's part of the game.''
AP Baseball Writer Ronald Blum in New York and AP Sports Writer Charles Odum in Atlanta contributed.