NHL.com continues its preview of the 2015-16 season, which will include in-depth looks at all 30 teams throughout August.

COLUMBUS -- The Columbus Blue Jackets set out this offseason to improve a defense that, along with an inordinate amount of injuries, derailed their chances of making a return trip to the Stanley Cup Playoffs.

Now about six weeks from the start of training camp, nothing has changed among the defense, which ranked 25th in goals allowed (3.02 per game) last season.

"I'm not concerned at all if we have to start the season with this group," general manager Jarmo Kekalainen said.

One of the reasons for his optimism is third-year defenseman Ryan Murray, the second pick of the 2012 NHL Draft. Murray, who missed 70 games last season because of injuries, is healthy.

Kekalainen did upgrade the Blue Jackets offense in the offseason. Columbus acquired Brandon Saad, along with two minor leaguers, in a trade with the Chicago Blackhawks for center Artem Anisimov and forwards Marko Dano, Jeremy Morin, and Corey Tropp.

Saad, 22, helped Chicago to a second Stanley Cup in three seasons in June. He had 23 goals and 52 points in 82 games in 2014-15 and had eight goals and three assists in 23 playoff games.

Saad likely will be on a line with center Ryan Johansen.

"Whoever you end up with, you're going to be playing with good players," Saad said. "But I know playing against [Johansen], you notice him a lot, especially when he had the puck. He has skill. He can finish and create plays."

The addition of Saad and the belief that the Blue Jackets can't possibly match their NHL-high 508 man-games lost has optimism high in Columbus, which finished 42-35-5 after ending the season on a 12-0-1 run and with wins in 15 of the final 17 games.

"It shows the character we have on this team and how close we are to being a great team," said forward Nick Foligno, who recently was named captain. "We easily could have gone a different direction. We were playing hard, trying to get better. That's going to bode well for the future."

Second-year center Alexander Wennberg (four goals, 20 points in 68 games) should take on a bigger role in Anisimov's absence.

Wennberg, Dano and fellow rookie Kerby Rychel (three assists in five games) were thrown into the fire prematurely early in the season because of injuries and weren't NHL-ready.

"The confidence [Wennberg] got the last little while of the season was huge," left wing Scott Hartnell said.

The Blue Jackets also lost versatile fourth-line center Mark Letestu, who signed a free agent contract with the Edmonton Oilers; center Gregory Campbell, who signed as a free agent, will replace him.

Campbell (Boston Bruins, 2011) and Saad are the only Blue Jackets who have won the Stanley Cup.

"That's the kind of experience we're hoping to bring to this organization," Campbell said.

Two of the injured players were forward David Clarkson, who was acquired from the Toronto Maple Leafs for Nathan Horton on Feb. 26 but played three games before a season-ending torn oblique muscle, and forward Rene Bourque, who was acquired from the Anaheim Ducks for defenseman James Wisniewski on March 2 and had four goals in eight games but missed the final 10 games because of a stress fracture in his back.

Offense should not be a problem with Foligno (31 goals), Hartnell (28), Johansen (26) and Cam Atkinson (22) leading the way, but the Blue Jackets will need a big season from 2013 Vezina Trophy winner Sergei Bobrovsky (30-17-5, 2.69 goals-against average, .918 save percentage last season) and improved play in front of him.

Murray, 21, will anchor the defense despite his youth and inexperience. Jack Johnson, 28, and Fedor Tyutin, 32, will provide leadership and minutes among a group that has six of eight defensemen 26 years old or younger.

"Our D will improve. [Bobrovsky] is always pretty solid," Hartnell said. "I like what we've got going here. We've got very deep forwards. We need to have a good summer and get excited for this season and pick up where we left off."