"The kid was going to get run over. I just kind of put my arm out and stopped him," he said.
It turns out the boy, named Patrick McCarthy, was already a fan of A-Rod.
"This guy just put his hand in front of me and stopped me. ... He said, 'Whoa, watch out, buddy,'" McCarthy said in a television interview Thursday. "I was like, 'Wow!' Like I was shocked, because he's my favorite player on the Yankees."
Rodriguez said he also had to hurry to avoid being hit by the truck -- "I almost got it, too," he said -- which he estimated was traveling 40-50 mph when he saw the boy starting to run from the sidewalk.
He said McCarthy's mother saw what happened, but he didn't see the boy's father nearby.
"I did it and I just kept walking," Rodriguez said. "I don't even know if she knew who I was."
Tuesday was a day off in the middle of New York's three-game series against the Red Sox that ended Thursday night with Boston's 8-5 win.
Rodriguez said the boy would have been seriously injured or killed had he gotten past him.
"That was a train wreck waiting to happen," he said.
Rodriguez has often been booed at Fenway since he joined the Yankees last season. Teammate Derek Jeter didn't think Rodriguez's heroic act would make Red Sox fans like him any more.
"They didn't sound any different today," Jeter said.
Copyright 2005 The Associated Press. This story was not subject to the approval of Major League Baseball or its clubs.