this player's showing a very nice bulge, and it doesn't look to be the result of a cup:
Football Bulge by boxjock78, on Flickr
hot shirtless side bulge going on during practice:
American Football Workout Shirtless by aelfrice, on Flickr
nice jockstrap lines visible:
Chargers jockstrap by boxjock78, on Flickr
very nice bulge and ass here, with the strap showing too!
FB 35 by dickgrayson66, on Flickr
nice bulge on the right, nice ass on the left:
Navy's bulges by boxjock78, on Flickr
this player certainly appears to be wearing a cup...
FB 27 by dickgrayson66, on Flickr