BAR HARBOR – In the seven years Mark Shields was an assistant football coach at MDI High, he backed up longtime coach George “Toogie” McKay, just as an assistant should.

But McKay resigned earlier this year after 22 seasons, and Shields is making a lot of changes.

“Pretty much everything is going to be different,” Shields said before the second of a double session on a recent afternoon. “The way we warm up, the structure of practice is completely different. Not to say that what Toog McKay did I didn’t agree with, because I did, but that was his system. My style’s just a little bit different than his.”

Shields isn’t the only face new to the MDI program. The Trojans have a big group of 23 freshmen, three more players than the other three classes combined. It makes for a lot of dedication and enthusiasm, but not much experience. So MDI is looking to its seniors.

Senior John Lewis will be a huge key for the Trojans. Lewis has struggled with ankle injuries in the past, but although he’s healthy now, Shields is still concerned about tiring out the standout back.

“Because of our numbers problems, unfortunately those guys are going to get a lot of reps,” Shields said. “Fatigue will probably be a factor in some games. But John is going to be the workhorse for us.”

Lewis, who was MDI’s second-leading rusher last year, said he’s prepared to be that workhorse. He’s gained about 30 pounds thanks to dedicated weightlifting sessions.

“Yeah, I’m probably going to be looked at a lot,” Lewis said. “It’s my senior year and I’m in the best shape of my life.”

Lewis’ twin brother Isaac will also play in the backfield.

Another plus for the Trojans is the return of junior Dale Beaudoin, who started at quarterback last season. Although Lewis’ presence should make the ground game a focus, the Trojans feel the 5-foot-11 Beaudoin can throw, too.

“We’re ex-pecting a solid season from Dale,” Shields said. “Obviously, we’re going to run the ball mostly, but we are going to open it up a little bit. He’s got a strong arm.”

MDI will run an I-formation offense set with a variety of different looks.

“We have a strong senior line, some talent in the backfield, and Dale’s got some skill, I think,” said senior lineman-linebacker Zack Carney. “He’s strong. He can take a few good hits.”

Shields said Carney is his top lineman, along with seniors John Reeves and Willie Fellis. Lewis will depend on those guys.

Defensively, Lewis and Carney will be the team’s top linebackers.

The Trojans are going to run a 5-2 defense. They ran a 4-4 base last year.

“We feel we’re going to be fairly strong in the middle with those two guys,” Shields said. “They’re two pretty big horses.”

Starting cornerback positions are up for grabs, Shields added. It all depends on what happens with the younger players. He already likes their leadership skills.

“I’m hearing them during drills saying, ‘Come on, guys, MDI pride,’ which you rarely see from ninth-graders, especially ninth-graders practicing with upperclassmen,” Shields said. “And we’re seeing that. We’re really excited about that, but obviously our focus is the upperclassmen and getting them ready to play.”

MDI TROJANS

2002 results: 2-7, sixth in LTC Class B

Head coach: Mark Shields, first year

Key players: John Lewis, RB-LB, Sr.; Zack Carney, OL-LB, Sr.; Mark Nichols, WR-DB, So.; Isaac Lewis, FB-DE, Sr.; Sam Burns, FB-DB, So.; John Reeds, OL-DL, Sr.; Willie Fellis, OL-DL, Sr.

Outlook: Carney is a leading candidate to handle the punting, while Nichols could be the team’s placekicker. The Trojans’ youngsters will have a tough test in their first few games. MDI opens with a road trip to Greely of Cumberland Center, then hosts defending Eastern Maine Class B champ Belfast. Shields has a very experienced defensive coordinator in Ian Braun, who coached the Old Town football team for seven years. The Trojans are waiting for some players to get cleared academically.