Question: What is the birthdate of this former American football player in the NFL, widely recognized as one of the greatest tight ends in the league's history, who was brought in as commissioner of the Indoor Football League?
Sentence (from "Kellen Winslow"): Kellen Boswell Winslow Sr. (born November 5, 1957) is a former American football player in the National Football League (NFL).
Relevant evidence: Yes