Mark Warburton's Glasgow Rangers side were soundly beaten by the Premier League outfit.
The Swiss international has been linked with a move to the City Ground.
The London club's visit to Australia saw a number of young players catch the eye.
Celtic were beaten 3-1 by Barcelona on Saturday evening.
The Championship side will be looking to secure an instant return to the top flight.
Glasgow Rangers boss Mark Warburton makes an admission following his side's 3-1 defeat at Ibrox on Saturday.
The Ghanaian is having a medical with German side Schalke 04.
The midfielder is the only major signing to arrive at Arsenal so far this summer.
The Argentina international has enjoyed a turnaround of fortunes at White Hart Lane.
West Ham United goalkeeper Darren Randolph has impressed for both club and country over the past year.