Martinez, a baby-faced rookie at just 22 years old, is the first to admit that he is surprised to find himself at such a defining moment in his young career.
"I never thought I would get here this fast," Martinez said smiling as reporters gathered around him. "I fought. I worked hard and here I am. I'm happy St. Louis gave me the opportunity."
Martinez will take the mound against the Red Sox sometime during the next eight days, get a sign from Cardinals catcher Yadier Molina and unleash a fastball that's been clocked at 100 mph or a biting breaking ball that can freeze hitters. The Cardinals fell in love with Martinez's teenage arm the first time they saw him work out in the Dominican Republic.
The Red Sox did, too.
If things would have worked out differently, Martinez would be pitching for the Red Sox -- not against them.
Instead, the former Red Sox prospect known as Carlos Matias is making a name for himself in St. Louis.
"It's in the past, so what can you do about it?" Red Sox international scouting director Eddie Romero said. "There's no reason to spend any extra energy on wondering 'What ifs?' All 30 teams would like to have a 21-year-old with that kind of arm and athleticism, but there's a reason that things work out the way they did."
Martinez likes to say, "It was just meant to be." The Cardinals are overjoyed with the way it has turned out.
Martinez allowed one hit and struck out four in 4 2/3 innings in four games against the Dodgers in the National League Championship Series, limiting Los Angeles hitters to a .077 batting average. The rookie gave up one run on two hits in two innings against the Pirates in the NL Division Series and has been pitching in high-pressure situations at the end of games since the end of the regular season.
He'll likely pitch in the eighth inning against the Red Sox.
"Carlos has electric stuff, there's no question about that," Cardinals manager Mike Matheny said. "But he has an incredible advocate behind the plate. How this all started, it happened in Milwaukee, where Carlos came in to close out a game and the first couple of pitches didn't look right. Yadi quickly went out there and had a couple of things to say, and had some force behind him. The next thing you know, there's no turning back. "
Overall, Martinez went 2-1 with a 5.08 ERA with 24 strikeouts in 24 1/3 innings during the regular season this year and 6-3 with a 2.49 ERA in 16 starts split between Double-A Springfield and Triple-A Memphis. He made his pro debut in the Dominican Summer League in 2010 at age 18. He was selected to pitch in the 2011 Futures Game in Phoenix the next year.
"It's always surprising when a young player makes the big leagues in three years because that's not normal, and to have it be an amateur you signed at 18 adds to that," said Cardinals international scouting director Moise Rodriguez. "The fact that he is there is not as incredible as the fact that he is pitching in such high-leverage situations and succeeding. Carlos does not get there without hard work and doing things the right way, so needless to say, there is a lot of pride involved already from our side and credit due to him."
Few know Martinez's unorthodox path to the big leagues better than Rodriguez. The story starts with the pitcher's birth in September of 1991 in Puerto Plata, Dominican Republic. When he was eight months old, his mother died. Raised by his grandmother Marta Martinez and his uncle Winton, a former ballplayer who signed with the Tigers, Martinez grew up without a father.
"My grandmother is my mother, she's my father, she's everything to me," Martinez said. "She raised me and gave me a chance at a future, health and education, and I'll never forget that. My uncle is like my father, helped me be a man. They are the ones that help me keep everything in perspective, even now."
It was Winton and Marta who eventually "declared" Martinez's birth to the Dominican government under the Matias surname. That decision complicated matters years later when the Red Sox signed him for $150,000. The pitcher failed Major League Baseball's identity investigation and as a result, was suspended for one year.
"We had him at our academy back when we signed him back in February 2009," recalled former Red Sox international scouting director Craig Shipley, who now serves as a special assistant to D-backs general manager Kevin Towers. "He was around 89 mph to 91 mph. He was athletic, had some sink and other things you like. He didn't pass the investigation and the contract was voided. Once a player's contract is voided, you don't usually end up back with same team, and he didn't."
The Cardinals conducted their own investigation and pleaded their case. The club eventually signed Martinez for $1.5 million in April of 2010.
"The stuff you see today is what we saw when we worked him out back then toward the latter end of his suspension," Rodriguez said. "We realized he wasn't lying. He never changed his birthday. This happened when he was a baby. I'm just glad we didn't give up on the case because it would have been very easy to walk away from cases like that because of the frequency of fraud in the D.R."
Marta, Winton, Martinez's wife and 3-year old son are all in St. Louis and will be at Game 3 when the series returns to Busch Stadium on Saturday. He and his wife are expecting their second child next year so it's understandable that he chooses to focus on the future, not the past.
"There was a time I thought my future was over and I would never play baseball again. I wouldn't be able help my family," Martinez said. "The Red Sox wanted to sign me and it didn't work out, but I'm here now and it's where I belong. I didn't plan it like this, but everything is the way it is supposed to be."