I wonder how long he has not been well. I think I recall that when the Phillies tried putting together one of the reunions for the 1993 team, he had proverbially gone off the grid and they weren't able to get in touch with him to invite him.
Sorry to hear, though. The article mentions the large number of Phillies from the Veterans Stadium era who have died of brain cancer...Oates, Vukovich, McGraw, Daulton. It left out Ken Brett. Considering that neither the Phillies front office from that time nor the Eagles organization (field or front office personnel) has had a similar brain cancer cluster, yes, it's probably an eerie coincidence.