BEREA, Ohio -- Cameron Erving called his rookie season "a really good learning experience" on Tuesday. A baptism by fire seems a more apt description.

Erving, the 19th pick in the 2015 draft, was viewed by many on the outside as the heir apparent to Pro Bowl center Alex Mack, a free agent who did the expected and signed elsewhere this off-season. Erving spent his first year, though, bouncing between guard positions, first filling in for Joel Bitonio at left guard then, after getting benched, moving to right guard for injured veteran John Greco.

"We can say it hurt me," Erving said about bouncing between unfamiliar positions last season, "but at the end of the day it was the hand I was dealt. I'm an NFL player. I'm a professional. It's my job to adapt to whatever position I'm put in. I'm not going to sit here and say, 'Yes, I was put in bad situations,' but it wasn't the greatest circumstances. But at the end of the day I don't blame the coaches. I don't blame anybody. I blame myself for whatever happened to me, good or bad."

There was plenty of bad last season, the lowlight of which was getting bull rushed by Steelers defensive lineman Cameron Heyward that left Erving flat on his back. The replay on CBS inspired Vines that went viral on social media and opened Erving up as an easy target for anyone looking to point out the obvious drafting flaws of then General Manager Ray Farmer.

"I always use stuff like that as motivation," Erving said of criticism during last season. "I felt like most of my problems came from technical, not as much physical. Of course everyone wants to be stronger. I can't say I didn't take heed of those things and I heard them. I definitely had that in back of my mind the whole off-season that I was training."

Erving, who previously trained at EXOS in Florida, decided to train this season at EXOS in San Diego.

Cameron Erving said on Tuesday that he is focused on playing center and has added muscle.

"Change of scenery," Erving said when asked about the change. "I heard the training was really good out there, so I tried it out and it benefited me."

Erving said he worked with former Dallas Cowboys offensive line coach Hudson Houck.

"It was me and a couple guys," Erving said. "He worked with the combine guys who were there, but he came in to work after they finished their combine prep with me and a couple other guys in the NFL."

"He came back in good shape," Bitonio said earlier this month. "Me, him and John (Greco) have been kind of working out together in the weight room and stuff. He seems like he is as strong as ever. I didn't really work out with him too much last year, but he seems like he is strong. He is running well. We were doing a lot of like, competition running today, and me and him were together on that. I was impressed with him. I felt like we were pushing each other, and he has been doing a really good job in that sense.

"I think that is one thing is that he is a competitive kid and he wants to come in here and prove that he was a first-round draft pick for a reason. I think he set his mind this off-season to come and make those changes and really try and fight and prove himself this year."

Erving said he is probably about 320 pounds -- "I'm probably a little bit heavier now," he said, "but I put on more muscle" -- and estimated that he lost about eight percent body fat.

"I feel like I'm really strong right now," he said. "But last year I feel like a lot of people said it was strength issues. I feel like it was more technical issues, me not having the right technique for what I was doing. I wasn't weak then."

Aside from adding strength, Erving is expected to focus primarily on playing center, at least for now. He said it will allow him to have a "clear mind and it gives me a better focus."

"I think it's a little too early," head coach Hue Jackson said on Tuesday about Erving being ready to take over for Mack. "I think, obviously, Cam has some ability and some characteristics that we love and we're going to continue to coach him and get him better. I think he's worked his tail off to come back here prepared and willing to accept the challenge, but, again, I'm sure if you talked to our players, each and every one of them is going to tell you they're just going to put their head down and work as hard as they can and they're not going to get worried about what's this or what's that right now. I think it's way too early to worry about those things but I think all of our players understand, to be a part of this organization, this football team, you've got to compete and you've got to become the best that you can become at your position."

"You can't replace a guy like (Mack)," Erving said. "You can only come in and create your own identity and that's what I plan on doing."

The success of the offensive line could hinge on Erving remaking his identity from overmatched rookie to heir apparent done good.