The New York Mets, who are closely trailing the Atlanta Braves in the NL Wild Card standings, have temporarily lost a key player in their lineup. J.D. Martinez, the team’s designated hitter, has been placed on the paternity list as he and his girlfriend, Brooke Wheeler, expect the birth of their first child. During his absence, which could last up to three days, the Mets have called up outfielder DJ Stewart from Triple-A Syracuse.

This roster change coincides with an upcoming six-game homestand for the Mets, starting with a series against Martinez’s previous team, the Boston Red Sox. Martinez, who joined the Mets on a one-year, $12 million contract right before the season started, has been performing well recently. Despite a slow start due to a back issue and late signing, he has delivered significant results with a .777 OPS, 16 home runs, and 65 RBIs in 105 games this season.

To cover for Martinez, the Mets have promoted Stewart, who had been sent down to Syracuse following the acquisition of Jesse Winker at the trade deadline. In his recent stint in the minors, Stewart has excelled, hitting an .879 OPS with some additional power and speed.

As the Mets aim to catch up to the Braves, who themselves have a seemingly lighter schedule, every game will count, making Martinez’s swift return important. He is eligible to rejoin the team as soon as Tuesday, depending on family developments, as MLB’s paternity list allows a player to miss one to three games.