Stokes, 20, has struggled to hold down a first-team place at the Stadium of Light during the club's time in the top-flight.
However, he rejected a loan move to Elland Road last season and McAllister does not want to renew his interest..
"He was a player we enquired about last season and he didn't want to come here," he told the club's official website.
"If players are reluctant to take an opportunity here then it's not something we pursue, so that was the end of it as far as I'm concerned."