It's a tough spot. I think either player could have AK (AKs in spades esp) here given the action and I suspect utg could have 99 in his range, but other 9x hands are unlikely. As well as this, utg has bet into 2 players which shows alot of strength, and it seems unlikely worse hands would bet here.
On the other hand, you are given great pot odds and its conceivable he is spazz bluffing the scare scard/betting tt/88 for value (less likely than bluff i think)
Overall in this spot I'd trust my stats/reads as to what to do but if I don't have them I'm leaning toward a call.