On the Bubble SnG situation

4 people left in a single table SnG. I am dealt A5s in 1st position and have about average chips (2300). Villian is a mediocre to average player, not too aggressive not too passive. He is the loosest person on the table right now. Big blind is 200. I come in for 600. He calls, making the pot 1300, and leaving me with about 1700.

Flop is A67. he checks, I bet 700. He puts me all in for about 1000 more.

What is your opinion on what I should do here?