Salam alaikum, I do believe this going to be some kind of surprise for majority of shias.
Your shaykh, ibn Babaweyh al-Qummi, which was Saduq in accordance to you, said in his book “al-Khisal” (p 158):
The compiler of the book – may God be pleased with him – says, “I heard my shaykh Muhammad ibn al-Hassan – may God be pleased with him – narrate that As-Sadiq (alaihi salam) said, ‘Zubayr was one of us -Ahlalbayt, until his Farkh (1) grew up and turned him from his view.’”
1) Muhaqiq said: He meant his son Abdullah.
Farkh = Little chicken (or bird).