ORONO — Before he could become one of Maine’s “big skilled” players, Carlton Charles had to become a little less big.

The would-be defensive lineman showed up for practices before his freshman football season weighing nearly 270 pounds. He had taken a year after graduating from Windham High, getting his academics in order so he could qualify to play at the Division I level. He had apparently devoted some of that time to eating.

“I was chubby,” Charles admitted.

He’s down to 235 pounds these days and preparing to have a big impact as a fullback when his senior season begins at 6 p.m. Saturday with a game against Norfolk State.

It’s not the most glamorous position, but just being on the field will be special for Charles, who has battled injuries throughout his Black Bear career. First, there were back problems, which cost him the entire 2012 season. Last year he injured his fibula in an October game against William & Mary, cutting that season short after seven games.

“My health is good, finally,” Charles said. “None of my previous injuries has bothered me this preseason. I’m going harder in practice, not stopping plays early and just giving better effort. I’m setting a better example for the younger players.”

Charles can fill a vital role for the Black Bears as an explosive lead blocker for tailbacks like Nigel Jones. He has come to relish the opportunity to knock opponents backward while someone else gets the glory.

His value is not lost on Coach Jack Cosgrove, who likes to use tight ends, H-backs and fullbacks to steamroll opponents from time to time.

“He really did a nice job of kind of reshaping his body,” Cosgrove said of Charles. “We wan, in certain situations, to employ a more physical type of personnel grouping. Closing out games, four-minute drills, situations where the clock becomes important, situations where you want to send a message of physicality.

“He can block off the edge, he can block power for us, he can catch the football in play-action. We know we can release Carlton in the flat. We can throw the ball to him.”

Charles made that apparent to his coach during his freshman year in a game at James Madison, when he ran a wheel route and made a terrific catch for a 21-yard gain right in front of Cosgrove. The coach recalled looking at Charles’ older brother, Raibonne, a star defensive lineman, and both saying, “Wow, did Carlton just do that?”

It was one of only four catches Charles has made for the Black Bears. So far.

“I’m a lead blocker mostly,” Charles said. “I’ve pretty much always been up close blocking people. I like that. It’s a good challenge.

“But I can be a receiver at times, on little dump-off routes, stuff like that. I’m trying to make the most of my opportunities and do whatever it takes for us to have a successful season.”