TAMPA—Hours before a game last September, word went around the Yankee clubhouse that hitting coach Kevin Long wanted to gather the entire team for a rare meeting.

Soon, the players were huddled up, and Long told them about Bridget, an 11-year-old girl they had never met, the daughter of Ron Johnson, the first base coach for the Red Sox.

Bridget, Long said, had been in an accident. She was riding a horse alongside the road in August, near the Johnsons' Tennessee home. A driver came around the corner a little too fast and plowed into Bridget's horse, severing the young girl's leg above the knee.

Bridget survived, and doctors re-attached the leg—but her body rejected it, and it had to be removed. She would need a prosthetic leg, and although the Red Sox had been financially generous to Johnson, money was still a problem, Long told the roomful of Yankee players.

Johnson had been Long's minor-league manager in the mid-1990s. When Long's playing career was winding down, Johnson helped Long get his first coaching job, with the Kansas City Royals—even going to management on Long's behalf when a promised job offer didn't materialize. It was a debt Long always wanted to repay.