If we rotate better and use him more often, I think Thiago would be content, because he knows he'll replace Xavi in a few years time. The problem isn't that Thiago's not a starter or the fact that Cesc is there, the problem is Tito's shit rotation. Cesc doesn't hugely interfere with Thiago's playing time, or at least he wouldn't with better rotation. After all, Cesc can't play the Xavi role while Thiago can, and Xavi needs to be rested often due to his age and all. Just use Cesc as Iniesta's backup and Thiago as Xavi's backup, and they shouldn't interfere too much with each other's playing time. Again, we just need better rotation.
And again, 3 players for 2 positions is not enough, especially when (as Stric said) one of those 3 is 33 years old. We need the depth, so we need to keep both Cesc and Thiago. I can't believe people are seriously suggesting that we sell Cesc and use 3 players for 2 positions next season.