The players are sweating it out at the stadium under the watchful eyes of their mentor Anil Kumble, former India captain and local man.
Mumbai Indians open their CLT20 campaign against Lahore Lions in the qualifying stage on September 13 (opening day of the tournament) in Raipur.
There are four teams in the qualifying round and two will make the main draw.
Three IPL sides, 2014 champions Kolkata Knight Riders (KKR), Kings XI Punjab (KXIP) and Chennai Super Kings have gained direct entry into the main phase of the tournament.
Mumbai Indians Squad
Rohit Sharma (captain, injured - doutbful for qualifiers), Harbhajan Singh, Ambati Rayudu, Pragyan Ojha, Praveen Kumar, Aditya Tare, Jalaj Saxena, Jasprit Bumrah, Shreyas Gopal, Mike Hussey, Kieron Pollard, Corey Anderson, Lasith Malinga, Marchant De Lange, Lendl Simmons