RENTON — Fans will be delighted to see Marcus Trufant back on the field for the Seattle Seahawks against the Dallas Cowboys on Sunday.

A lot of the rest of us are just pleased to see that he still exists.

Since the start of training camp, when he was sidelined with a vaguely defined back injury, Trufant was the invisible man. He was cloistered inside the facility; rehabbing, the staff said.

Poor guy never saw the light of day, and he certainly didn’t get to watch practices or be much a part of the team.

“I was like a ghost,” Trufant said Monday. “But I was in there grinding, working hard trying to get back.”

The value of his return for the 2-4 Seahawks is obvious. The Wilson High and Washington State product was a first-round draft pick in 2003, a Pro Bowl selection in 2007, and had missed just two games in his previous six seasons.

Only Walter Jones and Matt Hasselbeck have been with the Seahawks longer.

So he was not accustomed to dealing with a lost-time injury. And he’s not very good at pinpointing the cause or describing the nature of the injury.

“It was just a combination of things,” he said. “Sometimes with back (problems), they just come out of nowhere. I really didn’t know I had it, not really for sure. I ran well sometimes, but some days I could feel something. I finally got it checked out and they discovered I had a little back problem.”

He said he never felt as if it was an injury with “big-time pain,” but rather a gradually increasing problem. “Hard to put your finger on, just the daily grind of playing football.”

It landed him on the physically-unable-to-perform list, leaving him out of action through training camp and the first six games. These were challenges he hadn’t faced in the NFL.

“You feel kind of helpless,” he said of watching the team struggle. “At the same time, you have to be professional about it. If you’re injured, all you can do is try to heal quickly and get better. But if we’re not doing well, yeah, you get grouchy.”

Trufant is being eased back into action, practicing with the second unit Monday. Remember, not having had any training camp, he’s still in the learning stages with the Seahawks’ new defensive scheme.

“I’m playing catch-up right now, trying to cram it all in, like you’re cramming for a test (in college),” he said. “But I’m back on the field, trying to get back in tip-top shape while trying to get comfortable with everything. I’m soaking it all up and trying to put it all together.”

He’s doing more than that. After practice, he caught dozens of balls fired at close range by the JUGS machine, putting in extra work on the hand-eye coordination that might have suffered during the layoff.

“He hasn’t played football in a long, long time,” coach Jim Mora said. “He hasn’t been in a game since our last game last year. He didn’t do much in the offseason in terms of being able to condition for football. So we need to see where he is endurance-wise. Obviously, he’s got to knock some of the rust off in terms of his technique, but he’s doing that, and he’s worked hard.”

Technique? No problem there. Covering receivers in practice Monday, Trufant showed the fluid moves that made him such a high draft pick, retreating at speed, swiveling the hips on the turn, and closing the gap at the receiver’s break.

Mora was cautious in his evaluation, saying the Seahawks were going to wait until Saturday or Sunday to decide how much Trufant will play. But Trufant sure looked up to speed in practice.

Since joining the Hawks, Trufant has been extremely community minded, having founded the charitable Trufant Family Foundation. Aside from that, he’s appearing today at Wellington Elementary in Woodinville, speaking to students about the importance of youth fitness as part of the NFL’s “Play 60” program.

“Being involved with kids is something I love to do,” Trufant said. “Giving back to the community is a big thing for me. We’re trying to teach these kids to exercise 60 minutes a day, to run around and play sports, to be active and to get away from the video games and go out and just be a kid.”

Trufant is working hard to take his own advice, to be ready for Sunday’s game in Dallas, hoping to go out and play his first 60 minutes of the season for the Seahawks.