Brendan Rodgers lost his first competitive match in charge at Celtic.
Stylian Petrov is part of the Aston Villa squad who have been training in Austria over pre-season.
Stylian Petrov made his comeback in Aston Villa training earlier today.
Aston Villa's under-21's take on Arsenal in the play off final later this evening.
Stylian Petrov made over 300 appearances for Celtic during his playing days.