If leadership were the critical component of assembling an NFL roster, Jim Marshall would be heading into his 56th season as team captain.

So let's not overstate how much weight is really placed on strong leadership. A 23-year-old, off-the-charts blue-chipper who doesn't say two words and is voted most likely to be the next guy to get in trouble off the field will always trump the 33-year-old who is the perfect leader but is no longer as big or strong or fast or good as the kid.

It's the circle of life in athletics, particularly the NFL.

However, leadership is one of the many stones that get thrown onto the judgment pile when trying to piece a roster together. Vikings General Manager Rick Spielman is in the process of putting all of those stones on the scale when it comes to some of his older players such as 33-year-old linebacker Chad Greenway and 37-year-old cornerback Terence Newman.

Both are free agents with supreme leadership value and some gas left in the physical talent tank. Greenway wants to play another year. Newman hasn't stated his desire, but Spielman said Thursday that he believes Newman wants to play another season.

"I think there's a balance there," Spielman said when asked how he weighs leadership qualities. "You have young leaders that are willing to step up, but you can't discount the fact of that veteran leadership, too.

"I think last year was a key on some of our veteran leaders with this young football team. To have a Chad Greenway, to have a B-Rob [Brian Robison], to have a Terence Newman-type guy that can still contribute on the field, but also have that presence and that leadership to give that direction to those young guys."

Then there are some guys in the middle who aren't old yet but are no longer considered greenhorns. Guys such as Harrison Smith and Xavier Rhodes.

"What you're seeing now is, some of those younger guys that have been here for maybe one, two, some three years, with that established, when the new guys come in, you have that presence in the locker room that, 'This is the way we're going to do things.' And the young guys have a tendency to fall in line. But a lot of that is established by that veteran leadership. And it's established by, to be honest with you, Coach [Mike] Zimmer.

"It makes it easier, when you bring guys through, 'OK, this is the way we're going to do things around here. This is what happens in our locker room. This is how we handle our business.'"

Spielman seems genuinely interested in bringing Greenway and Newman back. He said he'll be having further discussions with their agents. But if they come back, it won't be just because they're great leaders.