That was because the team was honoring legendary Boston Celtics coach Red Auerbach, who died last year at the age of 89. Last week's originally scheduled celebration, which was to feature Bill Russell, Jim Loscutoff and Frank Ramsey, among others, was postponed because of wind and rain.
This time, the Red Sox managed to unfurl 16 championship banners from the top of the Green Monster -- from '57, '59, '60, '61, '62, '63, '64, '65, '66, '68, '69, '74, '76, '81, '84 and '86 -- and keep them there through the first pitch, a one-hopper down the middle by NBA Hall of Famer Bob Cousy.
This time, the weather allowed a sold-out Fenway Park crowd to witness the scene.
Celtics executive director of basketball operations Danny Ainge, a fan of the Sox's green jerseys, took in the atmosphere with reporters before the game.
"Red obviously means a lot to us and our tradition," Ainge said, "and it's great that the most popular team in town right now is honoring him right now."
Longtime Celtics star Tommy Heinsohn and current Celtics Ryan Gomes and Wally Szczerbiak participated in the celebration alongside members of the front office. Later, when the Red Sox announced the day's "medical all-star," Dr. William Maisel of the Beth Israel Deaconess Medical Center, Celtics managing partner Wyc Grousbeck said that Szczerbiak deserved the award.
Szczerbiak missed 50 games this season because of ankle troubles, one of many team injuries that derailed the Celtics' 2006-07 season. Szczerbiak laughed off the joke.
"I think [the decision to wear the green jerseys] is a very nice tribute to the Celtics," said Szczerbiak. "I hope it brings them luck."
He added, "I always love coming to Fenway. And against the Yankees, what better game to see?"
Gomes, before admitting his childhood allegiance to the Yankees, said it was nonetheless special that the Red Sox were "honoring somebody that's in a different sport." It shows "how much he meant to the city of Boston," Gomes said.
Just a half-hour later, the Red Sox took the field in their green jerseys and the crowd roared. On a sunny day in Boston, in first place in the American League East and with the Yankees in town, the fans were all too happy to show some pride.
New York City also displayed a bit of green on Friday night, with the top of the Empire State Building emanating a bright shade of green in honor of Earth Day.
Alex McPhillips is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.