You miss the point. Cahill himself hasnt performed, at all. Zat knight has been the better of two. The fact that he is in the england squad doesnt cover the fact that since february he has been terrible for bolton. If he keeps playing at this level for chelsea, then you have just thrown away money, and goals. He deserves all the flak he gets because he hasnt performed
Neither deserve any credit, in fact no Bolton player deserves credit. He is a good footballer and is now playing for a better team with much better teammates so he will improve.