It was reported that veteran batter Shikhar Dhawan is likely to captain India in the quadrennial extravaganza.
Harshal had a golden chance to tie the game and take the match into a 'Super Over'.
The Indian captain added he is fit to lead the side against Jos Buttler's England.
While the exact nature of his injury wasn't known it seemed like back spasms which can happen at times due to the extreme cold that one encountered in Perth.
Indian have been alternating between Karthik and Pant in their playing XI.
The veteran wicketkeeper-batter was included in the Indian squad for the T20 World Cup in Australia.
With the Asia Cup starting from August 27 in the UAE, the tournament presents a chance for India to sort out their playing eleven ahead of T20 World Cup in Australia.
Karthik said he was enjoying the finisher's role but it is a task where a cricketer will never be consistent, given the nature of the job.
Both Karthik and Pandya came up with reassuring performances in the five-match T20I series against South Africa, with the former scoring a match-defining half-century in Rajkot that helped the hosts level the series 2-2.
Karthik has scripted yet another comeback into the Indian team, this time for the five-match T20I series against South Africa in June, on the back of scintillating finishing touches for Royal Challengers Bangalore in league stage of IPL 2022.