Sell Team up rewards

I'm sure I'm not the first player to suggest this, but it would be amazing if we were able to "sell" the unwanted team ups (and maybe boosts?) we get as rewards from battles sometimes. Thanks Cap, but I really don't need a twelfth Sentinel of Liberty - esp if you're the 2* version. It would be very nice if we had the option to exchange it for something small, maybe even like 100 Iso-8. Anything. Would be better than just trashing it (even though many of them are indeed garbage).