Kohli, who skipped batting at nets on Thursday, has not yet fully recovered from his shoulder injury which he sustained in the third Test at Ranchi. (Worrying signs for India ahead of fourth Test; Kohli skips batting at nets)
Iyer is expected to join the team on Friday. The Mumbai batsman was initially named in the India Blue squad for the 50 over Deodhar Trophy tournament.
A prolific scorer in domestic, Iyer notched up 927 runs at an average of 54.52 with three hundreds and was also one of the main reasons for Mumbai to reach the finals of the current Ranji Trophy.
However, it is still not clear whether Kohi is ruled out of fourth Test or not as there has been no official statement from the BCCI. Clarity is expected on Friday evening.