Hundley also weighed in, congratulating Alonso for the record and saying, “To me, he’s more than a power hitter, he’s a pure hitter.”

Alonso has had his eye on the franchise mark since he smashed his 40th homer to break the National League rookie record on Aug. 18 against the Kansas City Royals. With a little over a month left in the season, Alonso will set his sights on the Major League Baseball rookie record of 52, set by Yankees outfielder Aaron Judge in 2017. Judge is the only rookie to surpass 50.

Alonso, 24, has been at the center of a Mets resurgence that thrust the team into the race for a wild-card playoff spot. The Mets entered the All-Star break with a 40-50 record, but are currently 67-64. They lost to the Cubs, 5-2, on Tuesday and fell three games behind them in the race for the second N.L. wild card spot.

“We know that we can play better,” Alonso said. “There’s a lot of season left.”

Alonso, known as Polar Bear among his teammates, has embraced the spotlight in his first big-league season. He won the Home Run Derby last month and, in addition to home runs, also led all rookies in runs scored, hits, walks and runs batted in.