Paul O’Neill vividly recalls his first visit to Yankee Stadium’s Monument Park, shortly after the November 1992 trade that installed him as the club’s sweet-swinging, hot-tempered right fielder -- a move that would later come to represent the dawn of a four-championship dynasty.

O’Neill first examined the monuments for Babe Ruth and Lou Gehrig, then moved to visit the permanent tributes to Mickey Mantle and Yogi Berra, absorbing the iconic names that established the franchise’s winning tradition. He instantly sensed the responsibility and weight of wearing the pinstripes.

“It was kind of a calling,” O’Neill said. “Once you walked into that stadium, it was like, ‘You know what? I’ve got to go see this.’ I had heard about the monuments. Going behind the outfield wall and seeing those plaques, the stories and the written things, it brought it all home. That’s where those things happen, in Yankee Stadium.”

Eight years after O’Neill was honored with a plaque in Monument Park, he saw his uniform No. 21 retired before Sunday’s game against the Blue Jays. O’Neill is the 23rd Yankees player or manager to have his number retired, and the first since Derek Jeter in 2017.

Guests on hand for the ceremony included Tino Martinez, Bernie Williams, Jorge Posada, Andy Pettitte, Mariano Rivera and former longtime head athletic trainer Gene Monahan. Video messages were played from David Cone, Joe Torre, Don Mattingly, Derek Jeter, plus one from Roberto Clemente Jr., who lauded O’Neill’s fiery “passion to win.”

“There’s so many dreams in life that don’t always come true,” said O’Neill, who received several gifts, including a custom-made wounded water cooler with No. 21 displayed on it. “That’s why I’m really celebrating this day, because this is the biggest dream that I’ve ever had in my life.”

Affectionately referred to as “The Warrior” by fans and known for his powerful throwing arm, O’Neill spent the final nine seasons of his 17-year Major League career in the Bronx (1993-2001), winning four World Series with the Yankees (1996, ’98-2000) and appearing in a fifth (2001).

• O'Neill reflects on No. 21 being retired by Yankees

O’Neill joined Jeter (No. 2), Posada (No. 20), Pettitte (No. 46), Rivera (No. 42), Williams (No. 51) and Torre (No. 6) in having their numbers retired from the dynasty era. O’Neill, who tossed a ceremonial first pitch to Posada, said that it’s “kind of mind-blowing” to think that the late 1990s clubs are so well-represented in Monument Park.

• Yankees' retired numbers

“Everybody might say, ‘Hey, that’s a lot of people,’ but a lot of good things happened in a short period of time there,” O’Neill said. “To win four World Series in five years, when is that going to happen again? So I’m proud to be associated with those teams.”

O’Neill recalled that the ‘Warrior’ nickname was given to him by George M. Steinbrenner, the Yankees’ late principal owner, as an homage to his hard-charging and intense demeanor on the diamond. Steinbrenner first made the comment after O’Neill’s performance in the 1997 American League Division Series against Cleveland, adding that O’Neill had “the heart of a lion.”

“Certain people are just wired certain ways,” O'Neill said. “Every at-bat, every game, every World Series meant a lot to me. Ever since I started playing sports against my older brothers, it was about winning and losing. It wasn’t about how you played; it’s who won and who lost.”

O’Neill concluded his Yankees career with a .303 batting average, 304 doubles, 185 home runs, 858 runs batted in, a .377 on-base percentage and an .869 OPS, claiming the American League batting title in 1994 with a .359 average. Additionally, he was a four-time All-Star with the Yankees (1994-95, ’97-98).

“He epitomized the tough at-bat,” Yankees manager Aaron Boone said. “He was a great two-way player. I wasn’t here for his last season, but seeing the video of the fans serenading him in his final season in that World Series, his final home game, to see him bubbling up with emotion in that game was one of those cool, cool moments.”

No. 21 has largely been held out of circulation since O’Neill retired following the 2001 season, for which he thanked equipment manager Rob Cucuzza during his remarks. It was briefly issued to pitcher LaTroy Hawkins in 2008; Hawkins requested the number as an homage to Roberto Clemente. O’Neill also thinks of Clemente being associated with No. 21, a number assigned to him when he joined the Reds in 1985.

“The first Major League Baseball game that I ever went to with my father, we were at Crosley Field in Cincinnati,” O’Neill said. “My father put me in a direction where No. 21 for the Pittsburgh Pirates was in the background, Roberto Clemente. And when I received the number in Cincinnati, that’s the first thing that came to my mind: ‘Wow, that was Roberto Clemente’s number.’ I still have the picture, and that’s kind of where this number became special to me.”

Currently a game analyst for the YES Network, O’Neill was previously celebrated at Yankee Stadium on Aug. 9, 2014, when he received a plaque in Monument Park. The plaque describes O’Neill as “an intense competitor and team leader” who “was beloved for his relentless pursuit of perfection.”

“To join these greats and to know that the No. 21 will never be worn by a New York Yankee again,” O’Neill said, “it’s by far the biggest personal honor that I’ve ever achieved.”

MLB.com’s Joe Trezza contributed to the reporting of this story.