Blue Jays shortstop John McDonald, a former teammate of Alomar's with the Cleveland Indians, also took part in the ceremony, speaking on behalf of the current Blue Jays.
"In 1994, I bought tickets to watch him play at Yankee Stadium, and I never thought that five years later we would be teammates in Cleveland," McDonald said. "Robbie is one of the greatest players to put on a Blue Jays -- or any other -- baseball uniform."
Alomar entered the Rogers Centre field through the crowd, who gave him a rousing standing ovation. It was the first of several throughout the roughly 30-minute ceremony, which featured a number of surprises, including a video message from Alomar's brother, Sandy Jr.
"You played the game the way it's supposed to be played," the former Major League catcher said. "We all love you and congratulations."
Gaston managed the Blue Jays for 12 seasons over two separate stints and presided over the team during some of its best years in the early 1990s. He presented Alomar with a special trophy to commemorate the retirement of his number.
"Robbie is the best second baseman to play the game," Gaston said. "I'm pretty sure I can speak for the city of Toronto, our fans, the organization and myself -- we'd like to thank you Robbie for all you've ever done for us."
Paul Beeston -- the Blue Jays' president and CEO who Alomar called his "second father" -- unveiled Alomar's center-field banner, which features a simple No. 12 with the Blue Jays logo from the early '90s and the logo of the National Baseball Hall of Fame, which Alomar was inducted into earlier this month.
"After 35 years, this is the first number that the Toronto Blue Jays have retired. I predict it will be many, many years until another number is ever considered," Beeston said. "We are going to do something today that will hopefully memorialize you forever."
Beeston went on to explain the memories and nostalgia he hopes the banner will spur in fans at Rogers Centre for years to come.
"There is going to become a time when a young generation of fans come into the ballpark and they're going to see that No. 12," Beeston said. "They're going to ask their parents, 'What does No 12 mean?' And they're going to say, 'That's the number of Robbie Alomar, the greatest second baseman who ever played the game.'"
Alomar was the final speaker during the ceremony and was interrupted several times by rousing applause from the packed crowd, which stood throughout his speech, at Rogers Centre.
"When I was a little boy, I never expected to have my number retired," Alomar said. "When I was traded to Toronto, I was blessed to come to play for a great city, a great organization, a great team, and to me, the greatest manager that I have ever played for."
At one point, Alomar asked his mother, Maria, and father, Sandy Sr., to join him at the podium.
"Today, we as a family, we want to thank you, the fans," Alomar said. "And I want to thank my family, because without them, I would not be standing here today. To my mom, my heart and soul, to my dad, who taught me everything I know about the game, thank you. I love you guys."
Alomar, who was traded from San Diego to Toronto in 1990, was a .300 career hitter who won 10 Gold Glove Awards and was named to 12 consecutive All-Star teams during his 17-season career.
He played for the Blue Jays until 1995, batting .307 with 52 home runs, 342 RBIs, 152 doubles, 36 triples and 205 stolen bases while wearing a Toronto uniform.
"I would love to see, every day, so many fans like I see today. Wow," Alomar said as he wrapped up his speech. "And to the 2011 Blue Jays, let's go."