BOURBONNAIS — The long-sleeved gray sweatshirt — even on a sunny, 90-degree day — is part of the go-to look for the Bears’ old-school defensive coordinator Vic Fangio.

Entering his 30th year as an NFL coach and 17th as a defensive coordinator, Fangio is not prone to hyperbole, especially seven days into training camp. So, even though several off-season additions have added talent and depth to last year’s defense — which was 14th in yards allowed — Fangio isn’t cranking up the rhetoric yet.

“I think we have a chance to be a better defense than we were last year,” he said, “but the proof will be in the pudding. Practice is the quiz; the games are the final exam. So, until we start playing and see exactly what we’ve got, that will determine the true answer to that question.”

That being said, Fangio has seen signs early in camp that bode well for the future. The offseason plan was to upgrade all three levels of the defense. The biggest addition, literally, was 6-foot-5, 336-pound unrestricted-free-agent defensive end Akiem Hicks.

“He’s done well,” Fangio said. “He’s a big, strong, explosive guy. He’s aggressive, he likes playing the game, (and) he’s enthusiastic. For a big guy, he’s got a lot of energy. We’ve just got to get him honed up a little bit better

in his techniques.”

The addition of veteran inside linebackers Danny Trevathan and Jerrell Freeman makes the Bears significantly better on paper. But Fangio says there’s still a learning curve before he can get more creative with the scheme than he did a year ago.

“We’ve got veteran guys, but they’re not veteran in our system yet,” Fangio said. “These first few weeks of training camp are all about fundamentals and techniques. When we lay the foundation for that and we see where we are, then we’ll see if we can start graduating from algebra to calculus.”

Possibly the biggest concern for Fangio is the uncertainty of outside linebacker Pernell McPhee. Last year’s big-money free agent was a focal point of the defense early in the season but ineffective in the second half. He had off-season arthroscopic knee surgery and hasn’t played football or even practiced since last season. McPhee isn’t even to the point where he’s performing football-related activities off to the side of practice with trainers.

“It’s a concern for sure,” Fangio admitted, “but until I see him out on the field, I’m really not thinking about it as much.”

Tempering the disappointment over McPhee’s absence is the improved health of outside linebackers Willie Young and Lamarr Houston.

Both came to last year’s camp dinged up from 2014 injuries and started slowly in the regular season. Both are 100 percent this year.

“They’re light years ahead of where they were last year at this time, so I think they should both make great improvements,” Fangio said. “They made great improvements through the season. Now, with an off-season and a training camp that they really didn’t have last year, they should even be better.”

Houston and Young combined for just 2 sacks through the first seven games last year but had 12½ in the final nine.

First-round pick Leonard Floyd is expected to provide another pass-rush threat at outside linebacker. Illness and a shoulder injury have limited his production in practice.

He’s flashed the first-step quickness that makes him a potential sack artist, but Fangio says his technique needs refinement.

“I think we’ve seen for the most part the player we thought we were getting,” Fangio said.

“He’s going to have to strike (blockers) a little bit better; he’s going to have to be a little quicker. He doesn’t have the physical advantage that he probably enjoyed most of the time in college, so he’s got to figure out the competition and adjust his play.”

If the front seven do a better job of pressuring opposing quarterbacks, the secondary will reap the benefits.

Veteran corners Kyle Fuller, 24, and Tracy Porter, 29, are back and solid, but the safeties are mostly 22- and 23-year-olds with limited experience, although Adrian Amos, 23, started all 16 games last year as a rookie.

“We’re young in the secondary outside of Porter,” Fangio said.

“We’re just going to have to see what they’re capable of doing mentally and what we can ask them to do effectively.”

Whatever the outcome, Fangio will remain calm.

“I don’t sweat that much,” he said when asked about the sweatshirt after three hours on the practice field. “I’m not a sweater.”