Joey Martinez

My stomach dropped when I saw, and heard, the ball hit Joey Martinez.

One, Martinez is one of the great guys. I talked to his mother, Toni, last week, and her son had failed to tell her about the award he had just gotten from his teammates, coaches and staff at spring training. "He's a man of few words,'' his mother said. Before today's game, I spent a few minutes with Martinez to get more background information.

And two, I know more than a little about head injuries.

My son, 16 at the time, sustained a traumatic brain injury in August 2006 when he fell off his skateboard without a helmet. He was in the hospital for three months. He missed nearly a year of school. He's pretty much OK now, though he has to take medication for seizures for the rest of his life, but it's been a long road. (I've written a book about the experience. It will be published in September.)

I'm sure Martinez will be OK. He was conscious. According to doctors at the ballpark, he showed no signs of a brain injury. He was heading to St. Francis Hospital for a CT scan and will be kept overnight. My thoughts go out to his parents and three siblings in New Jersey.

This season, Martinez has been sharing an apartment near the ballpark with Alex Hinshaw. Hinshaw and Martinez were drafted by the Giants in 2005. "He's the easiest guy to get along with,'' Hinshaw piped up in the clubhouse today when he saw me interviewing Martinez.

A little bit more background on Martinez:

* Martinez earned his degree from Boston College in finance and worked during one minor-league off-season at an insurance company in Boston.

*For two off-seasons, including this past winter, he worked as a substitute teacher at Columbia High in Maplewood, N.J., near the South Orange town where Martinez grew up. "It was mostly babysitting,'' Martinez said earlier today. "I only had to send one kid to the principal's office.''

* Toni is a teacher, as is Martinez's older sister, Angela.

* Martinez's father, Javier, was born in Cuba and moved to the U.S. when he was six years old. Javier's mother has a doctorate in math but earned her living in the United States as a high school Spanish teacher. Javier's father was an engineer. Javier Martinez graduated from college as an optometrist but now, like most of his family, he has also become a teacher.

* Joey's 23-year-old brother, Javier, was recently released by the Mariners organization and now is concentrating on putting his Fordham University business degree to good use. Andy, the youngest of the Martinez brothers, is a sophomore at Seton Hall Prep, the Catholic boys' school which all three brothers attended. Andy plays lacrosse.

*Martinez graduated from Seton Hall Prep with a 4.65 GPA. He was president of the Student Council and a member of the National Honor Society. Two of his closest friends were the valedictorian and salutorian. "We were geeks,'' Martinez said. Toni told me by phone from South Orange: "I remember once driving Joey and his friends to the movies when he was a sophomore in high school, and they were talking about their summer reading.''

* But, she said, her son has been crazy about sports since he was a baby. "Everything in his hand became a ball,'' she said. "He'd be playing with blocks and he'd be tossing them up in the air and catching them.''

*In high school, Martinez played four years of football, three of baseball and two of basketball. He still holds three school records in football and five in baseball.