He averages 4 in the current series and averages 18 with the bat in the 6 tests he has played during the year. This is his worst batting year since his debut. These are worrying signs for a batsman who has been, by far, the most consistent run maker post -2000.
Not only that but his slip catching is also not as sharp as it used to be, he has already spilled a couple or more catches during this series if i'm not mistaken?
All these are indications of slowing reflexes.
He will probably make pile up the runs against Unadkat/Sharma/Kumar etc. when the Indians visit SA later this year but they have a tough tour of Australia coming up next.
Should Kallis hang up his boots after the Indian series or do you think he can make a comeback?