[1] Lefferts moved to Sacramento, Japan, Topeka, Cape Cod and San Diego before the family settled in the Tampa Bay area.

[1][2] Lefferts' father wrote to his alma mater, the University of Arizona, and asked if his son could walk on to the school's baseball team.

Coach Jerry Kindall added Lefferts to the roster but cut him shortly thereafter as he was undersized (at 5 feet 10 inches (1.78 m) and 140 pounds (64 kg)) and did not throw hard.

Lefferts was traded from the Padres to the Orioles for Erik Schullstrom on August 31, 1992 in a transaction which was completed four days later on September 4 when Ricky Gutiérrez was sent to San Diego.

As of 2025[update], Lefferts is the most recent pitcher to hit a walk-off home run, doing so on April 25, 1986, in the bottom of the 12th inning against the San Francisco Giants' Greg Minton.