The era Chad Marshall knew had ended.

The stalwart defender had just finished his 10th MLS season with the Columbus Crew, seemingly an eternity in professional sports, and he took a look around this past offseason.

There was a new owner. There was a new coach. Departures of veterans Danny O’Rourke and Andy Gruene­baum meant almost everyone from the 2008 MLS Cup-winning team was gone in just a few years.

“It seemed to be like I was the last one,” said Marshall.

“They were obviously starting over, and I thought it was as good a time as any to maybe look at going somewhere else.”

Marshall got his fresh start when the rebuilding Crew traded the 29-year-old to Seattle for allocation money and a third-round draft pick. And the Sounders? Well, they just might have acquired the best defender in franchise history.

At a towering 6 foot 4, Marshall is the centerpiece of a reworked defense that has two shutouts in its first three games. He was named MLS Defender of the Year in 2008 and 2009. He wins nearly every header in his vicinity (leading some to call him the “Air Marshall”).

And he has his teammates raving.

“In my mind, the best defender in the league,” said midfielder Brad Evans, lauding Marshall’s physical presence.

“Honestly,” added defender DeAndre Yedlin, “he may be the best center back I’ve ever played with.”

A rejuvenated Marshall has been aided in his transition to Seattle due to a number of old Columbus connections. Coach Sigi Schmid led the Crew for three years before coming to the Sounders after the 2008 championship. Evans and assistant coach Ezra Hendrickson were former teammates in black and yellow.

Even those who had never met Marshall, though, have been instantly impressed, including center-back partner Djimi Traore, who has played with some of the best in a career that includes seven years at Liverpool of the English Premier League.

“I can tell you he’s a very, very good player,” Traore said of Marshall. “I can see his quality, and if he keeps going like that, I think, for me, he has a chance to play for the national team.”

The national-team argument is one Schmid had made for years, particularly as Marshall claims just 11 international appearances for the United States, a relatively low amount considering his prolonged MLS dominance.

Schmid, since 2007, has argued that Marshall has been overlooked by the USMNT.

“I think his quality is comparable to center backs who are in the national team pool right now,” the coach said Thursday. “I think his quality is better than some guys who have been called in (some recent) circumstances. … For me, he’s a quality center back, as good as any center back in this league.”

If there was ever a criticism of Marshall, it’s that he has lacked motivation at times in Columbus. In response, Schmid noted: “I think whenever you’ve been at a place for a long time, maybe a change of scenery is good for you.”

That change is at the center of this week’s challenge. Marshall, for the first time, has to face his former team, the only other professional team he has ever known, as the Sounders host the undefeated Crew at 7 p.m. Saturday. Marshall said the experience will be “a little different,” but the soft spot is clear. “I spent 10 years there, so I’m always going to be a fan of theirs,” he added. “Just not this week.”

Joshua Mayers: 206-464-3184

or jmayers@seattletimes.com.

On Twitter @joshuamayers