Peterson's son, whose name hasn't been disclosed, died Friday of injuries sustained in a beating at his home Wednesday.
The NFL player flew to South Dakota to see his son earlier in the week, but returned to Minnesota, saying he intended to play Sunday's game against the Carolina Panthers. He sent a text message to Fox Sports reporter Laura Okmin explaining that decision.
"My brother passed the night before the combine and I decided to go through with it. The same reason why I will play this week. You may ask why? God wants good to come from it ... We mourn and grieve but heaven had the baddest welcoming party for my son. That knowledge gives me peace. I'm still hurt and feel the pain of life, but I'm able to function because of the peace and joy of knowing my loved ones are in a much better place," he wrote.
Sioux Falls, S.D., police charged Joseph Robert Patterson, 27, with aggravated assault and aggravated battery on an infant in the incident. Patterson was dating the boy's mother.