Before this season, Le Toux was selected by the Union in the expansion draft.
The success of the Seattle franchise has been stunning. Commissioner Don Garber said that last year, just two of the 15 teams showed a profit - Toronto and Seattle.
It's easy to see why Seattle was profitable after drawing a league-high average attendance of 30,897 at Qwest Field.
According to team officials, tonight's opener is sold out. The stadium holds 35,500 for soccer.
It wasn't just the number of fans who showed up last season, but also the enthusiasm they displayed for the Sounders, who were 12-7-11 and won a playoff berth before losing in the first round to Houston.
"For me, it's the best place in the U.S. for fans," Le Toux said yesterday before the Union went to Qwest Field for a workout. "They are singing throughout, and it's a very special place to play."
Le Toux, who started 15 games and had one goal and three assists for Seattle, says his new teammates, especially the young players, have been asking him all week about the environment the team will face.
He has tried to steer them to focusing on the task at hand.
While conceding that he was disappointed when Seattle put him in the expansion draft, Le Toux is thinking of only one thing - beating his former team.
"I really liked playing for the city and team, but now I feel fortunate playing for Philadelphia," he said.
The most lasting impression of competing in Seattle that players have is the sheer noise.
"I love playing in Seattle, with 30,000 people on their feet for 90 minutes, and it is as close as a European atmosphere that you will get," said Union midfielder Shea Salinas, who played last season for the San Jose Earthquakes. "When they scored on us, I got chills, it was so loud."
But as much of a boost the crowd is for the home team, it also provides a spark for the visitors.
"You don't get tired playing in that atmosphere," Salinas said.