The most disturbing aspect of Ndamukong Suh's absence from the Detroit Lions' voluntary offseason program isn't that he isn't there. It's that his team doesn't have the courage to forcefully question that choice.

This essentially is one more example of why this franchise has enjoyed only two winning seasons in the past 16 years. It's also the first indication that Lions fans probably should brace themselves for more disappointment this coming fall.

The predictable defense of Suh -- who hasn't joined his team since voluntary workouts began last week -- is that these sessions indeed are not required. The three-time Pro Bowl defensive tackle hasn't participated in such events for the past couple of years, so it shouldn't be a big deal now -- or so the thinking goes.

When asked about it, quarterback Matthew Stafford said he expects Suh to be "in great shape" whenever the team starts mandatory workouts and minicamps. Lions president Tom Lewand and new head coach Jim Caldwell went a step further, saying that Suh could benefit from being around his teammates, but nothing they uttered be should confused with outright frustration.

What nobody was willing to say is what is plainly obvious to anybody watching this situation: It says plenty that Suh chose to not attend these workouts. Even if he's getting into phenomenal shape on his own, this was the first opportunity that Caldwell and his assistants had to educate their players on the team's new offensive and defensive schemes.

If Suh wasn't crazy about the team's philosophies on strength and conditioning, he could've seen the upside in that. These are the types of gestures that leaders make in order to foster a winning atmosphere.

The lack of irritation around the Lions suggests this is a team that has grown far too accustomed to dancing around their biggest defensive star. They surely understand that Suh's current negotiations for a contract extension might factor into his absence, which is fair.

But they also need to realize that changing the team's losing culture won't happen solely by taking a passive approach to what should be a more annoying situation. They don't need Suh to just make Pro Bowls. They need him to help build a sustainable foundation for success.

It's not as if the Lions have reached a point where they can operate like teams that actually do contend for championships. For example, it wasn't a major issue when former Chicago Bears linebacker Brian Urlacher missed some voluntary workouts in 2008 while fighting for a contract extension and former Bears head coach Lovie Smith pointedly said that he needed all his players available for those sessions.

But Urlacher also had led that franchise to several postseason games and a Super Bowl by that point. He had earned the right to vanish and the Bears had established a standard that younger players knew to follow. They could handle a couple weeks without their leader in the locker room.

The Lions don't have that luxury. They've made one postseason appearance since Suh's arrival as the second overall pick in the 2010 draft (a wild-card playoff loss to the New Orleans Saints during the 2011 season).

Suh's image around the league also has been a problem for most of the past three years. He has been suspended once, fined nearly $217,000 and also accused by Fox analyst Heath Evans of being "uncontrollable" in the Lions' locker room (Evans said three unnamed Detroit players gave him that news).

The team's decision to vote Suh as a captain should have been a huge turning point in his career. He clearly coveted the role, a desire that suggested he was prepared for the added responsibility. These are the kinds of things the Lions should be bringing up when they talk about his absence from these workouts.

He desperately wanted to lead this team last fall, and now he's sending an entirely different message with his actions.

If voluntary workouts weren't such a big deal, then Stafford might as well be training elsewhere. Pro Bowl wide receiver Calvin Johnson also could have taken a pass, along with any other player who had enough juice to do as he pleased.

Along with Suh, Stafford and Johnson are the most important players on the Lions' roster. They showed up because they know this was about more than getting into shape for the season.

Those players came because they realize this is yet another opportunity for the Lions to change their culture. Former head coach Jim Schwartz lost his job after last season once it became apparent that he couldn't sustain the momentum that blossomed during the 2011 success.

The team hired Caldwell with the hope he could provide the same calming presence that aided him as the Indianapolis Colts' quarterbacks coach and head coach and the Baltimore Ravens' offensive coordinator. The faster the Lions buy into Caldwell's message, the better their chances are of ascending to new heights.