Wrong Move?

[XXXNoahXXX]

$30+3 multitable on PP, I'm at 15K, average is 13K, down to 75, top 50 pay. It gets folded around to me on the button and I raise it $2500 with AJs. The BB reraises me all-in and I call. He shows A4, and hits his 4 on the river, to send me packing. My question is, do I need to bet more preflop, as all I really wanted was the blinds. I feel like he made his push because my bet looked purely positional, do I need to make it bigger to scare A4 out? The blinds were at 200/400 by the way.