This pick makes a lot of sense for the Lions, as Detroit doesn't really have a long-term option at defensive tackle on their roster right now. Butler is the 38th-ranked prospect according to SB Nation's Dan Kadar.
Now we'll have to see if Butler is there at 16 overall.
UPDATE: While the Lions obviously did not select Butler despite him being available at 16 overall, Butler continues to insist the Lions said they would draft him:
If it is correct that the Lions told him they would select him at No. 16 if he was available:
"That’s what they said, but they say a lot of things."