Given
this video (mentioned above) at 2:32-2:45, there is plenty of room for HIGH GOAL shots... looks like it's about 14-18" deep! The MIDDLE GOALs don't look as deep (~8" inches) but between the two MIDDLE GOALs, I'm sure they'd hold all the shots they'd get in a match!
Seems like a moot concern to me, based off those shots of the official field...