A more correct or complete answer is yes, but you might not like it.
I have a 5x8 trailer I pull behind my 4WD Sport Tracs. Both trucks have a Curt bolt on receiver hitch with a 2" drop ball mount. The 2" drop puts the top of the ball just above the surface where a ball would mount in the bumper. The trailer sits level with the 2" drop. A bumper mounted ball will be at least 2" higher and the trailer will likely not sit level. The rear of the trailer will drag going in and out of driveways that aren't street level, going over speed bumps, etc., especially if the trailer has 12" wheels like mine did when I got it. I upgraded to 14" wheels shortly after I bought the trailer. The Sport bumper isn't the same as the Sport Trac, but the ball mount surface is about the same height above the ground. If your Sport is 2WD, the bumper won't be as high, and the trailer will sit more level.
The other thing to consider is only 4 bolts hold that bumper on. That's not a concern in itself, but 2 of the 4 bolt holes in the bumper brackets are slots that allow some adjustment in leveling the bumper. When you see a bumper that tilts downward, you can bet someone's been towing with a bumper mounted ball.
