Here me out on this one. Let's say in your job there is someone who has the same postion as you do but it's ridiculously clear that you are a far superior employee. Now let's say the boss pays the other person a lot more than they pay you. Would you have a problem with that? Even if you are a team player would you deep down inside have a problem with that?
Now consider if Nazr Mohammed was given a contract that paid him alot more than Tim Duncan, though Tim wouldn't grip would he feel underappreciated?
Reason I mention this is because that's the situation the spurs have with Manu and Tony. Manu won't complain, but it may bother him enough deep down inside to keep him from having that little extra UMPH that takes him to even a higher level of play.
What do you think?