The signing of Oguchi Onyewu by A.C. Milan of Italy has raised the profile of American players in Europe and could help the sport in the United States.

A U.S.-born player, Oguchi Onyewu, took the practice field at the Georgia Dome on Tuesday with one of Europe’s premier soccer teams, A.C. Milan of Italy. Mr. Onyewu’s new teammates are some of the world’s top players, including Ronaldinho of Brazil and Italian Andrea Pirlo.

Mr. Onyewu, 27, who played at Clemson University for two years before going pro, is the first American-born player in A.C. Milan’s history. His signing has raised the profile of American soccer players in Europe and created new excitement about the sport in the United States just as Atlanta makes a pitch to host the World Cup tournament and ramps up efforts to land a Major League Soccer team. 

“Obviously this is a big step for me but also for American soccer,” Mr. Onyewu said in a Tuesday news conference the day before A.C. Milan’s match at the Dome against Club America of Mexico City. “I’m definitely hoping it will open doors for other Americans coming up. I’m definitely going to give everything I have and not disappoint anyone.”

The signing of Mr. Onyewu by A.C.Milan and two heavily-attended international soccer matches this summer in Atlanta will build momentum for the city’s efforts to host the World Cup in 2018 or 2022 and to get a Major League Soccer team here, said Scott Moran, an international attorney with Berman Fink Van Horn P.C. who is among the leaders of both efforts. “An American player for A.C. Milan, that is definitely a breakthrough,” said Mr. Moran. “It’s visibility, it’s credibility for the American players.” 

Umberto Gandini, organizing director for A.C. Milan, agreed. “I think the fact that Oguchi plays for A.C. Milan will be an inspirational moment for a lot of kids in America to think they can play in Europe, they can play for big clubs,” he said. “You have a lot of young talent coming up. You have an excellent national team. It’s no longer that United States soccer is far behind the rest of the world. You are definitely part of the global game.”

The only downside would be if Mr. Onyewu does not get much playing time for the highly-talented A.C. Milan team, said Mr. Moran.

Mr. Onyewu told reporters that he is taking nothing for granted and acknowledged the high caliber of his new teammates. “Obviously in football [as soccer is called in Europe] or any sport, there are no guarantees,” Mr. Onyewu said. “I came here with the impression that I have to fight for my spot. They have a number of great defenders on the squad.”

More than 50,000 fans attended the July 22 exhibition match. Club America won 2-1. Fans cheered when Mr. Onyewu entered the match in the second half.

The fans included young refugees, who are members of the Clarkston soccer team, the Fugees. They turned out even for the Tuesday practice session and sought autographs and cheered as their favorite players kicked goals.

A match last month in Atlanta between Mexico and Venezuela attracted an equally large crowd. Mr. Moran said this is only the opening for what he hopes will be a continuous series of soccer events leading to the World Cup in Atlanta and to a Major League Soccer team here. 

Atlanta’s current professional soccer team, the Silverbacks plays for the United Soccer League‘s First Division, a notch below Major League Soccer, which has attracted international stars such as David Beckham of the Los Angeles Galaxy.

Arthur Blank, co-founder of Home Depot Inc. submitted a bid last October for a MLS franchise but withdrew it because of the slowing economy. Atlanta could get another chance in 2013 when MLS is expected to add two expansion teams.

Reach Mr. Moran by calling (404) 261-7711.