Celtic midfielder Scott Brown says he is determined not to play catch-up with his team-mates after checking in to pre-season training a week late.
The club captain was forced to pull out of the Scotland squad for the World Cup qualifier in Croatia earlier in the month through injury.
Parkhead boss Neil Lennon gave the former Hibernian player extra time off to recover but Brown says he is now back and raring to go.
He said: "I'm only back one day and I've not trained with the squad, I'm doing my own running.
"I feel not too bad. I've not really done twisting and turning and passing the ball yet so I'm a bit behind everyone else, but I'll catch up soon."
Celtic face a crucial Champions League second qualifying round double header with Northern Irish champions Cliftonville next month, and Brown is under no illusions about the importance of the tie to the club's aspirations for the new season.
He said: "The Cliftonville tie is going to be huge. We have to try and get everyone fit and ready. It's hard to get everyone back into the squad on time but I'm sure the gaffer will do that."