City first lady Chirlane McCray has been hobbled by a third sports injury in the last three months.

Mayor Bill de Blasio’s wife sported crutches and a boot on her right foot Wednesday at a mental-health event in Brooklyn’s Borough Hall.

McCray, 60, was diagnosed with tendinitis likely from too many turns on the treadmill at the Park Slope YMCA, said an aide.

Over the Thanksgiving weekend, McCray posted a photo on her blog of two other sports injuries: a strained index finger from Wiffle ball and a wrist injury, requiring a brace, from a soccer game.

“I need to stretch a moment, I’m walking around with this boot and have the crutches,” McCray said Wednesday.