With British & Irish Lions fly-half Owen Farrell established in the number 10 jersey, questions have been raised over stand-off Lozowski's future with the Aviva Premiership giants.
Exeter Chiefs are thought to be interested in the 24-year-old's services but McCall is adamant Lozowski can shine in other positions at Sarries and work his way into Eddie Jones' England side on a regular basis.
"Alex understands 12 or 13 is going to be his route internationally," McCall told BBC Radio 5 live. "We are confident if Alex stays here he will play that 10, 12 or 13 role for us, and will be busy all the time.
"That's what Eddie Jones wants as well I'm sure."