Jozy Altidore has done slightly better at Hull, a team struggling to survive in the English Premier League, getting two starts and four substitute appearances in nine matches since his arrival.
American soccer players go to Europe by the dozens, but many struggle for playing time and the best somehow must remain sharp so they're ready when they return to the U.S. national team.
"It's a different world," Onyewu said, a day ahead of Saturday night's World Cup qualifier against Honduras. The U.S. would clinch its sixth consecutive World Cup berth with a win.
A 6-foot-4 defender from Olney, Md., Onyewu played for Clemson, signed with the French club Metz in 2002 and played for Standard Liege from 2004 to last spring, helping the club win Belgian league titles in his last two seasons.
He started at the 2006 World Cup, attracting attention for his size and physical play. While he made 11 appearances for Newcastle during a loan in 2007, he didn't stick, so it was somewhat a surprise when he was given a three-year contract in July by AC Milan, a seven-time European champion owned by Italian Premier Silvio Berlusconi.
The 27-year-old is stuck behind former Italian national team regular Alessandro Nesta and Thiago Silva, an occasional starter for Brazil. Although Onyewu saw time during AC Milan's U.S. preseason tour, he has appeared in just one of 10 competitive matches, making his official debut as a 60th-minute substitute in the 1-0 Champions League loss to Zurich on Sept. 30.
"Obviously, I haven't received as much playing time as I would like, but, you know, in terms of training, I'm definitely putting myself in a position," he said.
Altidore, a 19-year-old forward, has had an even harder time in Europe. After he joined Hull, the team signed Jan Vennegoor, of Hesselink, and the Dutch forward has settled into a starting role. Altidore's lack of action for his club could cost him with the national team.
"Whenever a player moves to a different club, or changes in a club in terms of management or different players that come in or out, there are challenges," U.S. coach Bob Bradley said. "That initial challenge of earning respect, getting on the field, there's no timetable there."
After U.S. captain Carlos Bocanegra established himself at England's Fulham, he didn't start for the final four months of the 2007-08 season after it became clear he would let his contract expire.
Bocanegra hopes Altidore isn't saddled with the "Freddy Adu tag" -- players with great expectations who went to Europe and fizzled.
"He needs to grow. He's done good things already, and, you know, he has the potential to do great things," Bocanegra said. "He has a few good games, is on top of the world, and the next thing you know, he's dubbed savior of U.S. soccer. And then, you know, he has a few games and everybody's slaying him, killing him in the press, and his confidence just goes. That's a hard thing for a young guy."