Former Celtic star Kris Commons reckons Ange Postecoglou will know he has to improve his rearguard ahead of next season.
The Premiership leaders are on the verge of title glory but were made to sweat by rivals Rangers during Sunday's 1-1 draw at Parkhead.
But that point keeps Postecoglou's men in charge as they close in on title glory in the Australian's first season in charge.