WSOPC $5K KK facing 4-bet (reality check)

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3rd level of tourney.
100-200 blinds. 10K starting chips.

Hero has 12K, villain about 16K or so.

Villain has been pretty active, but has never 4-bet preflop. Not once. At one point, villain took down a hand with T8o on a T-high board vs. hero's 99. Villain has also limped with 63s and made trips.

Hero has a fairly tight image, and has shown very few hands. One time showed AK calling a short stack's all-in.

UTG limps (as has been common)
folded to villain in MP who makes it 750
folded to Hero in LP with K [img]/images/graemlins/spade.gif[/img] K [img]/images/graemlins/diamond.gif[/img] who makes it 2250
folded to villain who makes it 5250

Hero?

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If there is going to be any discussion here, I'd like to know if anyone thinks that there is any line better than pushing? I assume no one folds, but is calling and evaluating the flop an option?

Also, does it matter if villain is a known pro or not?