How were 8 tight ends drafted before George Kittle in 2017?

George Kittle was drafted in the fifth round out of Iowa by the 49ers in 2017. He was the ninth tight end selected.

Jake Butt (5, 145)

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Jake Butt played college ball at Michigan. The Broncos drafted the tight end despite the fact he suffered  a torn his ACL in the 2016 Orange Bowl and suffered nerve damage which, prior to physical therapy, had completely immobilized his leg. Butt missed 2017 while rehabbing. He played in three games in 2018 with eight catches. On Sept. 2, 2019, Butt was placed on injured reserve due to complications with his previous ACL injury