Gambhir had not sought exemption for using corti injections

The letter that Kolkata Knight Riders physio Andrew Leipus wrote to BCCI regarding Gautam Gambhir's shoulder injury states that the player had used "corticosteroid injections" earlier.
Interestingly, the corticosteroid injection is under banned drugs list of World Anti-Doping Agency (WADA) and a sportsperson needs to get Therapeutic Usage Exemption Certificate (TUEC) from National Anti-Doping Agency (NADA) or WADA in order to use the drug.
According to Director-General of NADA Rahul Bhatnagar, neither the cricketer nor the BCCI had procured TUEC from the organisation.

"I can confirm that we didn't issue any TUEC clearance to Gautam Gambhir for using corticosteroid injections in the past. We have a three-member committee consisting of one doctor from the AIIMS and two doctors from Safdarjung Hospital who issue TUEC," Bhatnagar told PTI today.

According to Dr P S M Chandran, the President of Indian Federation of Sports Medicine, TUEC is a must for any sportsperson as there are chances that one may get caught if there is a random dope test.

"Sports doctors are normally cautious in giving steroid injections into joints as they are aware of the dangerous consequences of this injection. These injections give temporary relief, but when the athlete start taking heavy training load subsequently, the areas injected fail to cope up with the load," Dr Chandran said