Everyone handles traumatic/tragic incidents in their lives differently.
AD probably feels that playing football, will help him cope with the situation with his son.
Just because he intends to play on Sunday doesn't mean that he doesn't care about his son. Brett Favre played a game a day after his father died. That didn't mean that he did not love or care for him. A lot of athletes deal with tragedy in their lives by turning to their respective sports. I imagine doing what they do best is often therapeutic to them.
Might wanna stop jumping to conclusions.