PORT ST. LUCIE, Fla. — The day after Mets pitchers and catchers reported to the team’s spring training facility here a month ago, Sandy Alderson strolled through the clubhouse. He greeted each player by name, and a smile stretched across his face.

For a man requiring medical tests every four months to check if he remains cancer free, Alderson has remained as dedicated as ever to his work. And he has regained the 25 pounds he lost during 20 weeks of chemotherapy and two surgeries.

“My doctor says it’s good,” Alderson said. “My mirror says it’s bad.”

At 69, Alderson is the oldest general manager in baseball, a sport he once described as a young person’s game. His first year as a general manager was way back in 1983 with the Oakland Athletics, long before the data revolution transformed the sport.

All these years later, he now embarks on his seventh season with the Mets, a team that he took over in the midst of a financial scandal that significantly affected its payroll and then patiently rebuilt into a World Series contender.