After an offense finishes 29th in the league, changes should be expected. Not just with personnel but also coaching. Matt Nagy decided to make major tweaks to his staff this offseason, hiring four new faces. Probably the biggest surprise was dismissing the respected Harry Hiestand in favor of Juan Castillo who spent last year at Michigan.

Castillo and Nagy go way back to their time together with the Philadelphia Eagles. That familiarity no doubt played a part in the hiring. The head coach said as much in a recent interview. However, it wasn’t the only reason. Nagy felt something needed to change with how the offensive line was being coaching. That’s not to say Hiestand was bad, but it was implied his style just didn’t mesh with what Nagy wanted.

So what does he want? He explained in detail when asked during a recent press conference. By the sound of things, he fully expects Castillo to be on the butts of the offensive linemen constantly.

“For Juan, my history with him goes way back. I just know how he works. I know how he thinks and I have ultimate trust in how he’s going to build what he wants to do with that offensive line. Fundamentally he’ll have a plan. Schematically he’ll have a plan. As a teacher and as a friend with those guys he’ll have a plan. So from all those areas, he’s going to stress those guys in the right way and teach them how to play the game and how to do it the right way. There’s a big comfort there.”

Juan Castillo has a reputation for being relentless

Plenty of players have spoken glowingly about Castillo and his approach that made them better. At the same time, their words often came with a warning. Be prepared for an incessant and relentless personality. The offensive line coach is detailed to the point of obsession. Former Pro Bowl tackle Jon Runyan said it could really get on the nerves after a time. Some guys might not like it.

Perhaps that is exactly why Nagy hired him. He wanted somebody to come in and really push the offensive line room on details. On doing the little things right. This makes it easier to find out which guys have what it takes to handle the mental challenges of the NFL and who are leaning on their natural gifts too much.

If they can’t learn how to block properly with a guy like Castillo, they probably have no hope in the NFL.