Notre Dame and 2013 Irish opponent USC were the only schools with two players on the list.
Koyack and Niklas are both juniors, and the two are expected to split time at the tight end position this season as Notre Dame looks to replace last year's leading receiver, tight end Tyler Eifert.
Koyack appeared in twelve games last season and started the national championship game against Alabama. He had three receptions for 39 yards.
Niklas spent last season at tight end after coming to Notre Dame as a linebacker. He started seven games and had five receptions for 75 yards and one touchdown.
Eifert won the 2012 Mackey Award after hauling in 50 receptions for 685 yards and 4 touchdowns. No school has ever had two Mackey Award winners.