The Minnesota Twins catcher welcomed twin girls this week, the first children for he and wife Maddie.
Mauer left the team before Tuesday night's game against the Angels to fly home to Minnesota. He made it in time for the birth of Emily and Maren early Wednesday, according to Twins director of baseball communications and player relations Dustin Morse.
Mauer was placed on the paternity leave list before Wednesday's game. Catcher Drew Butera was recalled from Triple-A Rochester.
Butera, who spent the last three years as Mauer's backup, has been with Rochester all season, batting .215 in 79 at-bats after recovering from a broken left hand. Mauer, a six-time All-Star, played in 92 of the first 96 games until Tuesday.