SAN DIEGO -- It took only one day of practice for Antonio Gates to notice the change in his team’s defense.

The veteran tight end usually stays away from Chargers Park during the offseason to allow his body to heal from the rigors of a lengthy regular season. But Gates showed up for organized team activities (OTAs) on Wednesday, in part to participate in the team’s “Thank You San Diego Day” -- an event where players disperse throughout the community to thank fans for their support.

“I wanted to just be part of what we got going on, and to be part of a team,” said Gates, after riding the roller coaster with fans at Belmont Park in Mission Beach. “Obviously it says a lot about what we feel, and how we feel about the city and our fans.”

Chargers tight end Antonio Gates described the defense's work during OTAs as "unbelievable." Jeff Gross/Getty Images

After his first practice, Gates said he was impressed with how San Diego’s defense got to the football.

“I know if you want to win championships in this league, defense is a big part of that,” Gates said. “And our defense was flying around and looking phenomenal today.”

Gates said based on what he saw in his first OTA, he’d be shocked if the Chargers finished 4-12 again. Along with Gates, the Chargers have several playmakers on offense, including new additions Travis Benjamin and Hunter Henry.

The offensive line has returned healthy, and Matt Slauson adds a grinder’s mentality to the group at center.

But specifically, Gates praised San Diego’s performance on defense, and understands why Brandon Mebane would say the Chargers have more talent on defense than Mebane's former team in the Seattle Seahawks.

“After seeing them fly around today, I could see why he would say that,” Gates said. “But make no mistake about it, that defense in Seattle has a championship. They’ve done some things we haven’t.

“What I’ve seen today from a defensive standpoint was unbelievable. I’ve never been more excited to see these guys play in the opener in Kansas City -- just from the pass-rush ability, the coverage and the speed -- everything. I was like, ‘wow.’ And we have some guys that are still kind of banged up.”

Gates said he sees similarities between this year’s defense and how the Chargers performed in 2006. That’s pretty high praise, considering the Chargers led the NFL in sacks that season with 61 and finished with a franchise-best 14-2 record during the regular season.

“I was around in 2006 and that defense, and there’s a lot of similarities,” Gates said. “The leadership is there. But the biggest thing to me was the fact that they compete at a high level, and that’s kind of how it was with them. And I don’t want to compare the two, because it remains to be seen what we do as a team. But we’re going down the right track.”

Gates also met Henry, this year's second-round draft pick out of Arkansas, for the first time on Wednesday.

“He has all of the intangibles and the tools to be a successful tight end in this league,” Gates said. “And I think the one thing that stood out the most was just to see him in the classroom and his focus. I can tell that he’s one of those guys that wants to succeed.

“To me, that’s the foundation, understanding and believing in hard work. Obviously, he’s talented. But he has that foundation, you can tell that he’s an unbelievable kid and comes from a great background. I can sense that right off the bat.”