He always is unhappy at Sevilla for some reason. I think its built in the game. Its pretty much true to real life as he was pretty ****ed off after Sevilla refused to let him go to Chelsea. Anyway, I'd keep him for the season if he's got a long time to go on his contract. If you win a trophy or two, he might just becomes happy again. If you think you dont have a chance of winning any trophies, then sell him as he'll continue to be unhappy. And yeah, I'd look to get atleast 30M for him. See if Arsenal get interested in him and make an enquiry or an offer. If they do, you can try to negotiate some money and Eboue off them (they wont sell Sagna so dont try). He's a very good RB although a bit negative. If not that, then Rafinha, De Silvestri are two other options. It'll be hard to replace him though as he's by far the best RB in the game (and IRL
imo!). But if you can get De Silvestri, he blossoms into a very good RB too.