"The IPL Event Technical Committee has approved Praveen Kumar as a replacement player for Zaheer Khan for the remainder of the Pepsi IPL 2014 season," the IPL said in a statement.
"Praveen is eligible to play for Mumbai Indians with immediate effect."
Interestingly, Kumar had gone unsold at the player auction held earlier this year.
Zaheer had been ruled out of the tournament after suffering a severe side strain after bowling just three deliveries of his final over in Mumbai's game against Kings XI Punjab on May 3.