Socceroo Tom Rogic is still basking in the afterglow of Celtic's Old Firm success but is under no illusion as to how big a test they will face against Barcelona on Wednesday morning.

Brendan Rodgers' side head into the Champions League Group C opener at the Nou Camp on the back of a 5-1 win over Rangers on Saturday.

Relishing the challenge: Tom Rogic. Credit:AP

Hours later, an under-strength Barca suffered a shock 2-1 to newly-promoted Deportivo Alaves in La Liga.

However, the midfielder knows the Catalan giants will have all their top stars back for the visit of the Hoops.