In his O-line leading eighth Bengals season, left guard Clint Boling and his mates are pointing to new coach Frank Pollack's May grind.

The Bengals began their second week on the field Monday without helmets in something the NFL calls "Phase 2," of the voluntary off-season workouts. But the offensive linemen don't need their headgear to know new coach Frank Pollack is changing the way they think.

Not to mention move with a bevy of new techniques.

Pollack's up-tempo, physically demanding drills have emerged as one of the talking points of the sessions that aren't open to the media. In Monday's locker-room media availability his players confirmed there's a new approach up front. Now they're just wondering how much tougher it's going to be with helmets in two weeks.

"It's a lot different," said right guard Trey Hopkins, who is going to play some center this spring as No. 1 pick Billy Price's shoulder heals. "There's not much standing around. It's, 'Let's get out there, get to work and when we're in the classroom we'll talk about it.' It's about the physical reps and your mind has to be right … He'll make a point to the group and it's on to the next rep."

The line coaches who swapped jobs come from two different schools that have both had enormous success.

The Cowboys' Paul Alexander, the only line coach the Bengals had from Dave Shula's last full year to Marvin Lewis' 15th season, is the cerebral guru who uses the field as a classroom. Pollack, who coached the Cowboys offensive line to nine Pro Bowl berths in the last three seasons, is a '90s NFL lineman and a smart, resourceful mechanic schooled under the hood of several models. While Alexander preferred using mainly light blocking shields while teaching, Pollack has rolled out more equipment than a road crew battling with I-71.

There's the trap-and-chute, where the linemen must stay low near their stance and power through without touching a tight tunnel. The arches are also designed to keep them low when they simulate the movement in trap plays. There are pop-up bags, sand bags, and small tire-like pod objects that the feet must be balanced on while they catch medicine balls.

"I haven't seen those before," Hopkins said of the pods. "That's so you're able to sit in your stance … trunk strength."

New left tackle Cody Glenn says he had four different O-line coaches in Buffalo and has seen every kind imaginable. He calls Pollack, "a throwback O-line coach and it's been good."

One observation from the trenches is Pollack is "an attitude kind of guy. It's fun. It's kind of contagious. He was a player. He knows what we're going through. He brings energy every day."

No one is saying that either approach is better. Both are proven. Many of the Bengals' single-season and career offensive records were set with Alexander as the line coach.

Just different. And after the struggle of the last two years (41 sacks allowed in 2016, the fewest rushing yards in franchise history last year) different is what people want.