Every Common and Rare Pack will contain at least five (5) Athlete Items. A Common or Rare Pack may also contain a Wild Modifier, in which case, the Pack would contain six (6) Items: 5 Athlete Items, and 1 Modifier Item.
Every Epic Pack will contain at least ten (10) Athlete Items. An Epic Pack may also contain a Wild Modifier, in which case, the Pack would contain eleven (11) Items: 10 Athlete Items, and 1 Modifier Item.
Modifiers can be found in any of the Pack Types, but are least found in Common Packs, and most found in Legendary Packs.