Question: What is the birthdate of this English former footballer who played as a striker and who played for the 2012-13 Sheffield United F.C. season?
Sentence (from "2012–13 Sheffield United F.C. season"): Sheffield United Football Club participated in League One, the third level of English football in 2012–13, after having failed to win promotion, losing in the previous season's play-off final.
Relevant evidence: Yes