The 30-year-old said after Saturday's Game 3 win over the Miami Heat that he was fortunate to spend time with his wife over the last month while rehabilitating from an ankle sprain, and the two agreed it made sense for Hayward to remain in Orlando.
"We discussed it, we prayed about it, and I think it's probably best if I stay here and help our team," he said, courtesy of NBC Sports Boston.
The 30-year-old had said in July he was planning to leave the bubble at some point in September for the expected birth of his fourth child.
Celtics head coach Brad Stevens was not aware Hayward had now decided to stay with the team but said attending the birth "takes priority," according to The Athletic's Jared Weiss.
Hayward made his first appearance for the Celtics since Aug. 17 on Saturday. He recorded six points, five rebounds, four assists, and three steals in 31 minutes off the bench as the Celtics trimmed the Heat's Eastern Conference finals lead to 2-1.