Assignment, Exertion and Must do!

[gizmoh]

hey guys, question.
i have say, an exhausted uruk hai againt my opponents two towers block Rohan deck. He has Eomer out who bears a Rohan Rider's Mountpossession that states at the start of each skirmish involving bearer, each minion skirmishing bearer must exert.
Cool.
Does this mean then that my opponent cannot assign the exhausted Uruk Hai to Eomer because exhausted characters cannot exert?
Or does it simply mean he can assign the uruk to Eomer, but the uruk doesn't exert because he can't and u just fight the combat as normal?

Any help would be appreciated, 

[ket_the_jet]

Characters can be exerted infinite times.

Rather, if the character is exhausted, nothing happens.
-wtk

[Elgar]

Characters can be exerted infinite times.

Rather, if the character is exhausted, nothing happens.
-wtk

Characters can't be exerted infinite times.  A character can only be exerted X-1 times, where X= that characters vitality.

However, you are correct that in this example nothing happens.  There is nothing that prohibits the assignment.  At the start of the skirmish the horses ability triggers, of which the effect is to exert assigned minion(S). Since this is an effect (not a cost) we do as much as we can, and since the minion is exhausted, it won't exert.

[ket_the_jet]

I meant that a character can be exhausted infinite times, which I thought I clarified.
-wtk