Landon Donovan is among 11 players added to Jurgen Klinsmann's United States squad ahead of Saturday's friendly against Scotland.
Joining the midfielder who ended the English season on loan with Everton are AZ Alkmaar striker Jozy Altidore and Sporting Lisbon defender Oguchi Onyewu.
The German coach will select a final squad of 23 on Friday for the USA's next five matches.
Rangers' Carlos Bocanegra and Maurice Edu were in the initial squad of 16.
As were Aston Villa's Brad Guzan, fellow goalkeeper Tim Howard, of Everton, and Fulham midfielder Clint Dempsey.
But there is no place for Rangers winger Alejandro Bedoya, who endured a difficult debut season at Ibrox.
Houston Dynamo's Geoff Cameron, Brondby's Clarence Goodson and Nordsjaelland's Michael Parkhurst are the other defenders among the added 11.
They are joined by Sporting Kansas City midfielder Graham Zusi and strikers Terrence Boyd, of Borussia Dortmund, Santos' Herculez Gomez, San Jose Earthquakes' Chris Wondolowski and Juan Agudelo, who has just transferred from New York Red Bulls to Chivas USA.
Klinsmann says he is excited by the form of several of those additions.
"Michael Parkhurst is playing right now for the chance to be Danish champions," he said.
Altidore celebrates a goal for Alkmaar in the Europa League
"Gooch is playing in the Portuguese Cup final. Herculez Gomez is playing for a title in Mexico.
"Terrence Boyd won the title with Dortmund Under-23 team and they moved up from the fourth division to the third.
"It would be awesome for these guys to come in with their chests puffed out.
"The more success they have with their club teams, the more confident they are."
Klinsmann's latest additions add plenty of goalscoring prowess.
LA Galaxy's Donovan, who is in the national squad for the first time since September, is the USA's all-time leading scorer, while former Hull City loan signing Altidore finished his first season at Alkmaar with 19 goals, including four in the Europa League.
Wondolowski's 11 goals in 12 matches for San Jose means he topped the Major Soccer League's scoring charts, while Boyd found the net 20 times for Dortmund's second team.
Parkhurst's arrival at the US training camp has been delayed by his side's victory over Goodson's Brondby on Sunday, a result that put Nordsjaelland two points ahead of Copenhagen at the top of the Danish table with one game remaining.
The USA go into their match against Craig Levein's Scots on the back of four straight victories and follow Saturday's match with further friendlies against Brazil and Canada as they prepare for their World Cup qualifiers against Antigua & Barbuda then Guatemala.
United States squad
: Brad Guzan (Aston Villa), Tim Howard (Everton), Nick Rimando (Real Salt Lake)
: Carlos Bocanegra (Rangers), Geoff Cameron (Houston Dynamo), Edgar Castillo (Club Tijuana), Steve Cherundolo (Hannover 96), Clarence Goodson (Brondby), Alfredo Morales (Hertha Berlin), Oguchi Onyewu (Sporting Lisbon), Michael Parkhurst (Nordsjaelland)
: Kyle Beckerman (Real Salt Lake), Michael Bradley (Chievo Verona), Joe Corona (Club Tijuana), Maurice Edu (Rangers), Fabian Johnson (Hoffenheim), Jermaine Jones (Schalke 04), Jose Torres (Pachuca), Danny Williams (Hoffenheim), Graham Zusi (Sporting Kansas City)
: Juan Agudelo (Chivas USA), Jozy Altidore (AZ Alkmaar), Terrence Boyd (Borussia Dortmund), Clint Dempsey (Fulham), Landon Donovan (LA Galaxy), Herculez Gomez (Santos), Chris Wondolowski (San Jose Earthquakes).