NEW YORK -- For the big leaguers who saw him play, Roberto Clemente was a breathtaking talent and unmistakable force on the field who made a powerful impact on young ballplayers.

His selfless humanitarianism left a lasting impression, too.

Major League Baseball commemorated its 21st annual Roberto Clemente Day on Thursday, with festivities centered in New York, where the Mets hosted the Hall of Fame outfielder's former team, the Pittsburgh Pirates.

Clemente died in a plane crash at age 38 attempting to deliver relief supplies to earthquake victims in Nicaragua on New Year's Eve 1972. To mark the 50th anniversary year of that tragedy, more than a dozen winners of baseball's treasured Roberto Clemente Award for philanthropy and playing excellence joined Clemente family members at Citi Field for the pregame ceremony.

"The most important trophy that I have in my house. Because it's not just a trophy," said former Mets slugger and 2006 winner Carlos Delgado, like Clemente, a proud native of Puerto Rico.

Hall of Famers Dave Winfield and Jim Thome were among the Clemente Award winners introduced on the field before highlights of the 15-time All-Star's life and career played on the large video board in center field.

Players and coaches from both teams -- all wearing Clemente's No. 21, as did some others around the majors -- lined the baselines. Puerto Rican musician Jose Feliciano performed the national anthem of Puerto Rico and "The Star-Spangled Banner," and Clemente's 4-year-old grandson threw out a first pitch in an RC III Pirates jersey.

"It is a very special energy today," said Luis Clemente, Roberto's son. "The energy is totally different this year."

Clemente, a cherished icon in baseball-loving Puerto Rico, became the first Caribbean and Latin American player enshrined in the Hall of Fame in 1973.

The strong-armed right fielder won 12 Gold Gloves, four batting titles and the 1966 National League MVP award. He helped lead the Pirates to a pair of championships in 18 brilliant seasons and was the 1971 World Series MVP.

"I came in the league in '73. I knew who Roberto Clemente was and I was going to be a right fielder, so I watched the way he charged the ball, picked it up, threw people out. I wish [we] would have been able to play so we could test each other's arms. But he was an incredible player and an even more incredible human being," Winfield said.

"Before I go, man, that was one of the things that I wanted to do was win this Roberto Clemente Award, because it would just acknowledge some of the work that had been done throughout my career," he added. "I missed him by a year. But his legacy continues, and we're all part of that."

Clemente got his 3,000th hit in his final at-bat, a double off Mets left-hander Jon Matlack on Sept. 30, 1972.

"You look back through the history and some of the things he did and what he means," Mets manager Buck Showalter said. "It's a great thing baseball is doing.

"I think of him catching the ball down the right-field line and spinning and throwing," Showalter added, noting he swung a Roberto Clemente model bat in high school. "I think about his reckless abandon and how loud a runner he was. Can you imagine what it was like trying to tag him at second, coming in, back when you could actually slide with your spikes and stay hooked to the bag because it wasn't hard and plastic and slick?"

There has been a push in recent years for MLB to retire Clemente's No. 21 for all teams, the way the sport did in 1997 to honor Dodgers pioneer Jackie Robinson for breaking baseball's color barrier 50 years earlier.

"It's a situation where I think it is gaining more momentum," Pirates manager Derek Shelton said. "I think today's one of the best days of the year."