At the end of Quentin's second year he took a test to see what Discipline he would be in for the rest of his career at Brakebills.
The test came out inconclusive, and he was put with the Physical Kids by default because they had the fewest students. He was promised a second chance at a discipline the next year.
I'm up to the chapter Fifth Year and there's been no second test for Quintin.
When was he officially put in the Physical Discipline?