He simply needs to understand that the reason he hasn't played the role he expected to is because he hasn't been good enough. Drogba hasn't had his best season, but he's still a better player and has delivered in the bigger games.
If he's going to go anywhere, then it'll be Atletico maybe. Back to his old club; good place to try and rebuild his career.
Anyone saying they'd take him for £20m is daft. He generally hasn't been playing well for 2 years now, with the odd spurt of form here and there, one of them being recent. He's had so many false dawns of looking better in that time though.