When you see defensive tackle Dan McCullers, it's completely impossible not to notice his size.

At 6-7, 352 pounds, he is a mountain of a man, size you think he could solely rely on to plug any hole on the defensive line.

The reality of it though, there is a lot more to football for young players than brute strength.

"It's mental. I feel like it's 90 percent mental," said McCullers. "You have to take your work ethic, look at film, and practice your fundamentals. You can't just depend on size because the offensive linemen could be quicker, smarter. They have one key over you and it could hurt you.

"I have to work on the fundamentals, leverage. I feel like I can be a great player. I just have to keep getting out there and grinding."

McCullers, who first played football in high school, said he was behind the eight ball with his development but is now making the strides he needs.

"I am learning the game more," he said. "I have started to progress each year. We have some great coaches that will teach you fundamentals and get you ready for battle. I am going to take everything in and just keep learning."

Nobody has helped more in his development than assistant head coach/defensive line coach John Mitchell. Mitchell is heading into his 23rd year coaching the Steelers defensive line and when he tells a player something, they listen.

"Just every day his advice, you take it in," said McCullers. "He has taught so many great players here, so many great defensive linemen. Brett Keisel, Casey Hampton, all those guys. I am going to take everything in and learn all I can. He taught the best, so he is going to continue to stay on me. He is demanding, but I am going to take it in and keep working."

McCullers is hoping the work he puts in will translate into playing time this season. Starting nose tackle Steve McLendon signed with the New York Jets as a free agent this offseason, leaving a window open for McCullers to take advantage of.

"I have been here for two years but haven't gotten a lot of playing time," said McCullers. "I have been on and off the field. This year I am going to work my butt off and prove to the coaches I am capable of being a great player.

"It's a big step for me. I am ready to take it. I want to get better each and every day so I can go out there and play well for that Steelers defense."

McCullers is among the players taking part in the Steelers offseason workout program, something he knows can only benefit him.

"It's great to be back working out, getting in the best shape possible for the season," said McCullers. "We have a lot of work to do to get ready. With all of the guys coming back we are going to take it day by day and grind and get ready for the season."