The 45-year-old Kallis worked in a similar role with the Proteas last year in the Test series against England.
Former England seamer Darren Gough believes Buttler's place in the team is under threat and he "has got two Test matches to save his career."
The report claimed that the future of English cricket looked “greyer around the temples.”
Ashley Giles has claimed that he is not afraid of making tough coaching decisions.
Ashley Giles believes the England coaching job is the biggest in world cricket.
Afghanistan vs Zimbabwe - 1st Test
Afghanistan
Match begins at 11:00 IST (05:30 GMT)
04 Mar, 2021 09:30 IST
Narendra Modi Stadium, Motera, Ahmedabad
West Indies vs Sri Lanka - 1st T20I
04 Mar, 2021 03:30 IST
Coolidge Cricket Ground, Antigua
West Indies vs Sri Lanka - 2nd T20I
06 Mar, 2021 03:30 IST
Coolidge Cricket Ground, Antigua
West Indies vs Sri Lanka - 3rd T20I
08 Mar, 2021 03:30 IST
Coolidge Cricket Ground, Antigua
New Zealand vs Australia - 5th T20I
07 Mar, 2021 08:30 IST
Westpac Stadium, Wellington
New Zealand vs Australia - 3rd T20I
03 Mar, 2021 11:30 IST
Westpac Stadium, Wellington
New Zealand vs Australia - 4th T20I
05 Mar, 2021 11:30 IST
Westpac Stadium, Wellington
Afghanistan vs Zimbabwe - 2nd Test
10 Mar, 2021 11:30 IST
Sheikh Zayed Stadium, Abu Dhabi
West Indies vs Sri Lanka - 1st ODI
10 Mar, 2021 19:00 IST
Sir Vivian Richards Stadium, Antigua
West Indies vs Sri Lanka - 2nd ODI
12 Mar, 2021 19:00 IST
Sir Vivian Richards Stadium, Antigua
West Indies vs Sri Lanka - 3rd ODI
14 Mar, 2021 23:00 IST
Sir Vivian Richards Stadium, Antigua
New Zealand vs Australia - 3rd T20I
03 Mar, 2021 11:30 IST | 06:00 GMT
Westpac Stadium, Wellington
04 Mar, 2021 09:30 IST | 04:00 GMT
Narendra Modi Stadium, Motera, Ahmedabad
New Zealand vs Australia - 4th T20I
05 Mar, 2021 11:30 IST | 06:00 GMT
Westpac Stadium, Wellington
New Zealand vs Australia - 5th T20I
07 Mar, 2021 08:30 IST | 03:00 GMT
Westpac Stadium, Wellington
12 Mar, 2021 19:00 IST | 13:30 GMT
Sardar Patel Stadium, Motera, Ahmedabad
New Zealand vs Australia - 2nd T20I
New Zealand beat Australia by 4 runs
India beat England by 10 wickets
New Zealand vs Australia - 1st T20I
New Zealand beat Australia by 53 runs
India beat England by 317 runs
Pakistan vs South Africa - 3rd T20I
Pakistan beat South Africa by 4 wickets