And his former teammate Mortlock reckons Robbie Deans must pick the best side available and that means Smith.
''In my mind, George Smith is a freak,'' said Mortlock.
''He's easily close to world XV standard right now. Do you want to pick a player who's world XV or has the capability to be world XV?
''I know which way I'd go. If you want to beat the Lions, you have the best openside flanker in the team. Liam Gill is a fantastic talent, Michael Hooper has proven he has all the qualities as well.
''But on current form, George Smith is world class, has X-factor all over him. I want to see him playing against the Lions because you want your best team out there.''
Smith had initially only signed a short-term deal with the Brumbies but a season-ending injury to David Pocock has extended that stay.
He is now eligible for the Wallabies but his situation remains complicated by the fact he is still contracted in Japan.
But his predecessor David Wilson has backed a potential recall.
''There's great depth at flanker, but George brings a wealth of experience and if he continues to play well, you'd select him,'' said Wilson.
''I wouldn't hesitate in picking him. But he has to be consistent because Hooper and Gill are just behind him.
''Maybe the ARU needs to look at the rules and guidelines with eligibility but George has played almost a full season, you want the best players on the [Wallabies] team. You pick the best team available.''