Those matches will be played Sept. 6 at Costa Rica and Sept. 10 vs. Mexico at Columbus.
All three will be available to the Sounders on Saturday when they visit Columbus to play the Crew. However, they will likely miss the Wednesday home match vs. Chivas USA, the Sept. 7 home match vs. Chicago, and should be back but with questionable availability for potentially crucial Sept. 13 home match vs. Real Salt Lake.
Here is the full roster:
U.S. ROSTER BY POSITION GOALKEEPERS (3): Brad Guzan (Aston Villa), Tim Howard (Everton), Nick Rimando (Real Salt Lake)DEFENDERS (8): DaMarcus Beasley (Puebla), Matt Besler (Sporting Kansas City) John Brooks (Hertha Berlin), Geoff Cameron (Stoke City), Edgar Castillo (Club Tijuana), Brad Evans (Seattle Sounders FC), Omar Gonzalez (LA Galaxy), Michael Orozco (Puebla)MIDFIELDERS (7): Kyle Beckerman (Real Salt Lake), Alejandro Bedoya (Nantes), Michael Bradley (Roma), Mix Diskerud (Rosenborg), Fabian Johnson (Hoffenheim), Jermaine Jones (Schalke), Graham Zusi (Sporting Kansas City) FORWARDS (5): Jozy Altidore (Sunderland), Clint Dempsey (Seattle Sounders FC), Landon Donovan (LA Galaxy), Aron Johannsson (AZ Alkmaar), Eddie Johnson (Seattle Sounders FC)
More information at the U.S. Soccer website.
Here is the news release from the Sounders:
Seattle Sounders FC midfielders Clint Dempsey and Brad Evans and forward Eddie Johnson have been called into the U.S. National Team for 2014 FIFA World Cup Qualifiers against Costa Rica and Mexico.
All three players will join the USMNT following Saturday's match in Columbus and will miss Seattle's matches against Chivas USA on September 4 and the Chicago Fire on September 7.
The USMNT visits Costa Rica on September 6. Kickoff is set for 7 p.m. PT (beIN SPORT and ESPN Deportes Radio) from Estadio Nacional in San Jose. The team then hosts Mexico on September 10 at 5 p.m. PT (ESPN, WatchESPN, UniMas and ESPN Deportes Radio) at Crew Stadium.
Dempsey, 30, is the captain of the U.S. National Team. Dempsey's next cap will be his 100th, becoming the 14th player in USMNT history to reach the century mark. He ranks second all-time with 35 goals for the USMNT, and ranks ninth with 12 assists. He has scored five goals in eight starts for the United States in 2013, and has led the team in goals the past two years. Dempsey is tied with Landon Donovan for the most goals (12) for the USMNT in World Cup Qualifying.
Evans, 27, has 13 caps and one goal for the United States. He has earned seven caps in 2013, and scored the latest game-winner in USMNT qualifying history at Jamaica on June 7.
Johnson, 29, has 57 caps and 18 goals for the United States, including two goals and one assist in three Gold Cup games in July. Johnson leads all USMNT players with 13 caps in 2013, and his 11 goals in World Cup Qualifying ranks third all-time for the United States.
The USMNT currently sits in first place in the Final Round of qualifying, collecting 13 points from six matches. The top three teams in the Hexagonal automatically advance to the 2014 FIFA World Cup in Brazil, while the fourth-place finisher will contest a two-game playoff against Oceania region winner New Zealand.
The USMNT is riding a record-setting 12-match winning streak that began June 2 with a 4-3 victory against then second-ranked Germany in the Centennial Celebration Match and includes three wins in World Cup Qualifying and six straight victories en route to the 2013 CONCACAF Gold Cup championship.
Sounders FC visits the Columbus Crew on Saturday. Kickoff is set for 4:30 p.m. PT from Crew Stadium.