Dan Graziano joins SportsCenter to explain how Le'Veon Bell's history of missing games could lead to the Steelers using the franchise tag on him again. (1:20)

PITTSBURGH -- The Steelers told Le'Veon Bell last month they have a "strong desire" to keep him in a black-and-gold uniform for the rest of his career, general manager Kevin Colbert said.

That means doing a contract extension this offseason, which the team prefers over the franchise tag.

"We never will discount the use of the tag because that's collectively bargained," Colbert told reporters Thursday. "But, again, our goal is to have something done on a long-term basis.

Colbert notes the team can tag Bell and still sign him long-term but reiterated several times a long-term deal is preferable. That's the goal for Bell, who wants to avoid a repeat of 2017, when the star back missed all of training camp and played on a $12.1 million tag. This year, the tag is projected to fall somewhere around $14.5 million. The team can apply the tag between Feb. 20 and March 6, after which it would have until July 15 to execute a contract.

Asked if he's optimistic over a new deal, Colbert said, "I believe I am," in part because Bell was great on the field and in the locker room despite the absence of an extension.

Bell's 1,946 total yards in 15 games stretched his average to 128.9 yards from scrimmage per game since 2013, an NFL record since the 1970 merger for a player's first five seasons.

Le'Veon Bell rushed for 1,291 yards and nine touchdowns and added 655 receiving yards and another two touchdowns in 2017. Mark Alberti/ Icon Sportswire

The team is weighing salary-cap options -- the Steelers currently have around $7 million in cap space -- and free agency while negotiating with Bell.

"Le'Veon has been a great player for us," Colbert said. 'We think he can still be a great player from this point forward and we'd love for him to be a Pittsburgh Steeler for the rest of his career."

Part of that salary-cap evaluation is figuring out how to get better. Colbert acknowledged that the Steelers weren't good enough after getting bounced in the first round by Jacksonville. The general manager said the defense was sometimes overaggressive against the pass and under-aggressive against the run, giving up at least 150 rushing yards in three of their last six games.

Colbert acknowledged some members of the Steelers under contract might not be on the team in 2018.

"If we don't change the roster we had in 2017, what reason would we think there wouldn't be any difference in the results?" Colbert said. "We have to be ready to be better than we were last year."

One player who will be around next year in some capacity is linebacker Ryan Shazier, who's recovering from a severe spinal injury. Shazier is in outpatient therapy, and Colbert said the linebacker has been in the team facility nearly every day working out and watching film. Shazier's $8.7 million option in 2018 is guaranteed for injury.

"Ryan does as much for us as we do for him because the way he works at this, and the attitude that he's shown in his rehabilitation is really uplifting," Colbert said. "Never once has he said 'why me' and I know that's an uplifting gesture for us and those who deal with him."