Although most pitchers rest their arms during much of the off-season, deGrom plays catch nearly year-round with his father in his childhood backyard. Teammates joke that deGrom could roll out of bed and pitch, while others need hours to prepare their bodies. The day after starts, deGrom’s arm is sprightly enough to fling a football 50 yards.

“If I tried to do that, my arm would go flying with the football,” pitcher Zack Wheeler said, adding with a laugh, “He recovers well and his body treats him right, even though he probably doesn’t treat it right.”

DeGrom does care for his body; he is a professional baseball player, after all, making $7.4 million this season. He just does it a bit differently from many of his teammates. Nonetheless, it has worked.

From the start of 2014, the season in which he won the National League Rookie of the Year Award, to the start of this season, deGrom’s 2.98 earned run average ranked ninth — better than standouts such as Jon Lester of the Chicago Cubs, Stephen Strasburg of the Washington Nationals and Dallas Keuchel of the Houston Astros. He is lauded for his pitching smarts, too, not just throwing hard, and is 2-0 with a 3.06 E.R.A. to start this season.

“Jake’s got a routine that is probably different than 99.9 percent of the guys in here,” the Mets’ captain, David Wright, said. “He gets his work in and prepares, but there are just a few things about him that are offbeat.”

DeGrom was always thin but not tall. As a high school freshman he was 5-foot-2, but he hit a growth spurt at Stetson University, where he was a shortstop with a weak bat. He converted to pitcher before the Mets selected him in the ninth round of the 2010 draft. After struggling to add weight in the past — pitchers often seek more mass to help throw — he gave up. For the past several years, deGrom weighed 183 pounds.