NEW ORLEANS — The San Francisco 49ers had an N.F.L.-high nine players selected to the Pro Bowl this season. At this week’s media day, eight of them sat on podiums in front of television cameras and masses of reporters. The ninth, Mike Iupati, the starting left guard, roamed through the crowd with far less fanfare.

It would have been easy to mistake Iupati, wearing his jersey and no pads, for a fan if he were not 6 feet 5 inches tall and more than 330 pounds. His size, along with a Mohawk-style haircut and arms covered in tattoos, make him an intimidating presence, right up until he speaks.

Iupati is a 25-year-old run-blocking specialist from American Samoa described by teammates as gigantic, fearsome and a monster, but he speaks softly, even taking the time to politely correct a reporter who mispronounced his surname. (It is you-PAH-tee, not eye-ooo-PAH-tee).

“Mike is just goofy,” said Joe Staley, the team’s Pro Bowl left tackle. “He loves to have fun. He’s like a big kid, the biggest kid you’ll ever see.”