PokerStars No-Limit Hold'em Tourney, Big Blind is t800 (9 handed) from (Format: Bet The Pot)

UTG (t32950)
UTG+1 (t56820)
MP1 (t43000)
MP2 (t23652)
Hero (t17700)
CO (t34250)
Button (t8800)
SB (t21000)
BB (t43474)

Preflop: Hero is MP3 with , .
3 folds, MP2 calls t800, Hero raises to t3200, 4 folds, MP2 calls t2400.

Flop: (t7600) , , (2 players)
MP2 checks, Hero bets t4000, MP2 calls t4000.

Turn: (t15600) (2 players)
MP2 checks, Hero checks.

River: (t15600) (2 players)
MP2 bets t5600, Hero folds.

Final Pot: t21200

Results in white below:
MP2 doesn't show.
Outcome: MP2 wins t21200.

I cant put him on anything? AA, QQ, TT, 99?? AJ?

I check behind on that flop like every time.

On the riv i seriously doubt he would bet 1/3 pot with anything u beat on that board. And the fact that if u call and lose you'll only have a 5k stack with 400/800 blinds..i fold.

To be honest it looks like a donk with A3 or A4 or something.

Is it bad that I raise to 4k and just shove this flop?