Nelson de la Rosa, 38, fixture in Sox clubhouse during 2004

The unforgettable 2004 Boston Red Sox had a clubhouse defined by its eccentricities: shaggy hair, unkempt beards, a bloody sock. Amidst the "cowboy up" slogan and pre game sips of Jack Daniels, however, there was one quirk that championship season that stood out -- even at 2 feet, 4 inches.

The presence of Nelson de la Rosa , Pedro Martinez's pint-sized countryman from the Dominican Republic, became an accepted element of a fall that seemed to have no end of surprises.

Mr. de la Rosa died at 4:15 a.m. Sunday at Rhode Island Hospital, according to hospital spokesman Andrea Barbosa . His agent, Andres Duran , told the Associated Press that he died from unknown causes. He was 38.

"There were plenty of nuances to that 2004 team beyond the baseball," said Charles Steinberg , a Red Sox spokesman. "I think that he was one of the tiles in the mosaic, this friend of Pedro's, albeit diminutive in stature, who brought some tension relief and comic relief."

"It brings a smile to our face when we think of Nelson," Steinberg said. "It saddens us to hear the news because you have to remember, he was more than an amusing entertainer. He was a human being with a soul."

Martinez first carried Mr. de la Rosa into the Sox clubhouse in late September 2004. As the team's winning stretched into October, it became common to see Martinez triumphantly hoisting Mr. de la Rosa over his head.

"Nelson was a good friend and a loyal Red Sox supporter," Martinez said in a written statement released by the New York Mets through his agent, Fernando Cuza . "I am saddened by his loss at such a young age. My heart goes out to Nelson's entire family."

Mr. de la Rosa became sick Friday in Miami, where he had been working in a circus. On Saturday, he traveled to New York, then to Providence, where two of his brothers live, his agent told AP.

Born and raised in a small village near San Miguel, in Santo Domingo Province, the charismatic Mr. de la Rosa, who stood between 28 and 29 inches tall, became internationally known when he appeared alongside Marlon Brando in the 1996 film "The Island of Dr. Moreau."

After Martinez signed with the Mets during the 2004 off-season, Mr. de la Rosa was still on occasion spotted near Fenway Park. In spring 2005, he appeared at the Baseball Tavern on Boylston Street, where he posed for photos with fans. To get in the pictures, Mr. de la Rosa stood on a pool table.

Mr. de la Rosa's body will be sent back to the Dominican Republic after an autopsy , his agent said. He leaves his wife, a 9-year-old son, his mother, and five siblings.