Joe Torre, MLB's executive vice president for baseball operations, told The Associated Press the decision was made to keep policy consistent throughout baseball and that "certainly, it's not a lack of respect."
The Mets wanted to wear caps honoring police, firefighters and other first responders like the ones they wore on Sept. 21, 2001 in the first sporting event in New York after the World Trade Center attacks collapse 10 days earlier.
MLB issued a league-wide memo on uniforms for games played on the 10th anniversary, saying teams must wear their everyday caps with a small flag on the side.
Some Mets wore caps, such as "NYPD" and "FDNY," during batting practice. Mets player representative Josh Thole said he and his teammates were thinking about wearing those caps during the game.
Several minutes later he returned and said the caps were a "no-go" because he was told the league was adamant.
The Mets held 24-minute ceremony of remembrance under dimmed stadium lights before their game. Fans held electronic candles as bagpipers and drummers stood on the infield and first responders lined the basepaths. Each of the Mets and Cubs escorted a member of "Tuesday's Children," a charity for families impacted affected by the attacks, onto the field and they stood with the uniformed emergency-service workers.
A 100-by-300 foot flag was held by first responders and victims' family members.
Marc Anthony sang the national anthem, as he did on Sept. 21, 2001. Mike Piazza, who hit an uplifting homer in the eighth inning to help the Mets beat the Atlanta Braves that night, caught a ceremonial first pitch from John Franco, a teammate on the 2001 squad.