University of Maine’s Sterling Sheffield puts pressure on University of New Hampshire QB Trevor Knight during the 2017 season. (Portland Press Herald photo by Shawn Patrick Ouellette)

Sterling Sheffield has spent the last three weeks in California. But the University of Maine senior hasn’t spent any time on the beaches or touring vineyards.

He’s been too busy training for the biggest playing opportunity of his career.

Sheffield, a linebacker for the Black Bears the past four years, will play in the NFLPA Collegiate Bowl on Saturday at the Rose Bowl in Pasadena. This game is considered one of the premier opportunities for draft-eligible college players to showcase their skills for NFL scouts and coaches.

It’s not just the game that’s important, but every practice leading to it. Last year, former Maine offensive tackle Jamil Demby made a big impression the entire week and ended up being drafted by the Los Angeles Rams.

Sheffield, who was third in tackles (84) for the 10-4 Black Bears last fall, knows the stakes.

“Being able to have this opportunity is amazing,” said Sheffield, who has two more classes to take this semester. “It’s a showcase, so I might as well showcase my talents. Practices are going to be as important as the game, so I have to have the mentality to go out every day and ball out.”

Playing the Rover, or outside linebacker position, the 6-foot-2, 240-pound Sheffield was one of the defensive leaders of the surprising Black Bears, who advanced to the national semifinals for the first time. He finished with 9.5 sacks, 18 tackles for a loss, three fumble recovers and two forced fumbles. He was named a first-team STATS Football Championship Subdivision All-America linebacker and was a first-team selection in the Colonial Athletic Association.

“He definitely took a step as a leader this year,” said Mike Ryan, the new UMaine defensive coordinator who coached the linebackers last year. “He was leading by example, getting guys into the summer workout, in the weight room. He did everything we asked.”

Sheffield has been working out at the Mamba Sports Academy in Thousand Oaks, California, as well as at California Lutheran University. He’s been joined by many of the top senior players in the nation.

“There’s about 15, 20 of us,” he said. “We’re working out every day, except Sunday.”

Sheffield has been in touch with Demby, who is on the Rams’ 53-man roster. The two have gotten together a couple of times.

“He’s really helped me prepare for this,” Sheffield said. “He told me to keep working on my fundamentals and to make sure I’m confident every time I work out. And it’s helped.

“I’m learning to not be so uptight about everything, to just take it day by day and have fun doing it.”

Sheffield said a typical training day begins about 8 a.m. and ends about 5 p.m. and includes everything from stretching to positional workouts to weight lifting.

“It’s definitely helped prepare me for what’s next,” he said.