Creatures opponents control entering the battlefield don't cause backup abilities to trigger.
At the beginning of your combat step, detain target creature with backup or vehicle an opponent controls. (Until your next turn, that permanent can't attack or block and its activated abilities can't be activated.)
Near Mint - $32,300
Lightly Played - $25,900
Moderately Played - $22,600
Heavily Played - $19,400
Damaged - $16,200
Near Mint Spanish - $32,300
Lightly Played Spanish - $25,900
Moderately Played Spanish - $22,600
Heavily Played Spanish - $19,400
Damaged Spanish - $16,200