SEATTLE — At this point, the large crowds in Seattle are nothing particularly new.

The Sounders have been averaging around 40,000 fans per match for the past three seasons and just this past Saturday more than 53,000 showed up to see a game against the Vancouver Whitecaps.

But it's not just the sheer number of fans that has been leaving an impression on United States national team players in town for Tuesday's game against Panama (10 pm ET; ESPN/UniMas, LIVE chat on MLSsoccer.com) — it's the entire atmosphere surrounding the match.

“I heard there were many soccer fans, but I didn't know that much,” forward Terrence Boyd told reporters after Monday's training session. “This is a great commercial for MLS, what's happening right now. Fifty-thousand? Even in the Bundesliga, this is a big deal.”

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Midfielder Joe Corona said that when he and his teammates were walking around town in their training gear, he had the unfamiliar of experience of fans constantly stopping them to ask to snap pictures and get autographs.

While that may be seen as an inconvenience in some parts of the world, he said he appreciated the attention.

“It's amazing,” said Corona, who plays his club soccer for Club Tijuana of the Liga MX. “I've never expected it to be like this. People are into soccer, there's a spirit. That's very important for the United States. You don't see a lot of cities that follow soccer.”

For players whose memories of MLS predate the Sounders, the experience is especially satisfying.

“I remember when I first started out in MLS, things weren’t like that,” US captain Clint Dempsey said in a press conference Monday. “So it’s great to see that there’s markets like this that have so much passion for the game.

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“I almost felt like I was in another country the other day when the Seattle Sounders game was on – I was walking to get dinner, just as you walk past the bar, you see the TVs on and everyone’s watching soccer. So to me, that was awesome.”

While Tuesday's crowd won't be as big as the one to see the Sounders over the weekend, the players are clearly hoping the energy transfers over.

“Anybody who pays attention to MLS sees what a special thing they have going here in Seattle,” midfielder Michael Bradley told reporters at Monday's training. “Whether you've been to a game or just watched the highlights on the MLS website, you see how passionate the people here are and how much their team means to them.

"We hope when we step on the field, they can support us in the same way.”