New York Mayor Bill de Blasio throws out the ceremonial first pitch before Opening Day on March 31, 2014 at Citi Field. (Photo by Elsa/Getty Images) New York Mayor Bill de Blasio throws out the ceremonial first pitch before Opening Day on March 31, 2014 at Citi Field. (Photo by Elsa/Getty Images)

NEW YORK (CBSNewYork/AP) — It is a political rite of spring: the Mayor of New York City throws out a ceremonial first pitch and gets booed for his trouble.

Mayor Bill de Blasio took his turn on the mound for the first time Monday at Citi Field, donning a customized Mets jersey with his name on the back and smiled through the jeers as he took his place at the bottom of the pitcher’s mound.

De Blasio said before he took the mound that he would not be upset if he heard boos.

De Blasio soundly booed as he throws out the first pitch at Citi Field, as if it's his fault the Mets couldn't trade Ike Davis. — Brokelyn (@Brokelyn) March 31, 2014

Bill de Blasio was booed at a NY sporting event, he's now officially our mayor — Tim Baysinger (@tim_bays) March 31, 2014

“I’m a sports fan and I think sports fans have a right to express themselves any way they want,” he said.

The mayor, a serious sports fan, seemed to relish the opportunity to take the field on Opening Day, one of the city’s great unofficial holidays. He peppered his remarks on pre-kindergarten funding with jokes about baseball stats and revealed that he been practicing by playing catch with his son and aides at an athletic complex near his Brooklyn home.

“I was at the Park Slope Armory last night, working on my knuckle curveball,” he joked. “I look forward to debuting it today.”