To fix this, Kabam released Update 26.0. They removed the "Sell" button entirely.
Many new players want to delete their 1-Star or 2-Star champions to save space. Even low-tier champions have specific uses: how to sell champions on marvel contest of champions
Kabam disabled this option to prevent players from making "bad moves" that would hurt their long-term progression and roster diversity, especially for content like (Variants) and special Arenas that require specific low-rarity champions. 馃毇 Why You Can't Sell Anymore To fix this, Kabam released Update 26
The short answer is: you can no longer manually sell individual champions in Marvel Contest of Champions. To fix this
