The Mumbai Indians (MI), a five-time Indian Premier League (IPL) champion, are struggling in the ongoing 2026 IPL season, currently positioned in the lower half of the table after suffering their fifth defeat. In a recent match against their rivals, the Chennai Super Kings (CSK), MI faced a 103-run loss at their home ground, Wankhede Stadium in Mumbai. A significant controversy arose when MI replaced Mitchell Santner with Shardul Thakur as a concussion substitute, despite Santner only suffering a shoulder injury. Santner was injured while attempting a catch, leading to concerns in the MI camp, including from co-owner Akash Ambani. Questions emerged regarding the legitimacy of the concussion substitute, as MI had already utilized their Impact Sub option earlier in the match. While concussion substitutes are typically allowed for head injuries, MI may have argued that Santner's shoulder injury could have caused concussion-like symptoms. This interpretation, however, has sparked significant scrutiny and debate regarding the application of concussion protocols in the IPL.