Broken Promise

So I brought in Joaquin Correa and I promised him I would play him at CAM and I ended up finding a tactic that worked well with him at Left AM where he was also natural at. Now he's mad that I broke the promise. Is there any way to fix it without having to play him at CAM or do I have to sell him?

Just keep playing him. If he's a long term contract then I'm sure he'll become happy again eventually.