His wife, Morgan, had to prematurely deliver the baby at 4 a.m. Sunday morning.
"Although we are hurt, I am grateful for the experience and grateful that God blessed me with a wife as courageous and resilient as Morgan," Goodwin wrote. "The pain (physically, mentally, & emotionally) that she has endured is unbelievable. Please Pray for the Goodwin family."
Goodwin played in Sunday's game against the New York Giants hours after the family tragedy and contributed in what became the team's first win of the season. He scored an 83-yard touchdown and was clearly emotional in the end zone:
He was also one of only three players to kneel during the national anthem this week, along with teammate Eric Reid and Giants defensive end Olivier Vernon, according to the Associated Press.
Goodwin, who also represented the United States in the Olympics in track and field, is in his fifth year in the NFL and first with the 49ers.