One of the best linebackers in NFL history made a surprise visit to Detroit Lions minicamp Thursday, but Mike Singletary wasn’t really there for the football.

Singletary, who’s presently coaching high school football in suburban Dallas and will take over as coach of the to-be-named Memphis franchise in the new Alliance of American Football next year, stopped by the Lions’ Allen Park practice facility Thursday to check out the new video board at the team’s outdoor practice field.

More on that later, but since Singletary — one of the fiercest, meanest players of his generation — was on hand Thursday, I figured I’d ask him about the most noticeable change to Lions practices under Matt Patricia: all of the running.