Tournament rules allow four roster changes in advance of the quarterfinals.
U.S. coach Jurgen Klinsmann added Johnson, Matt Besler, Omar Gonzalez and Alan Gordon while subtracting Corey Ashe, Herculez Gomez, Jack McInerney and Oguchi Onyewu.
The U.S. opens the knockout stage Sunday against El Salvador. The tournament final is July 28.
Here's the release from the Sounders:
Seattle Sounders FC forward Eddie Johnson has been called into the U.S. National Team for the 2013 CONCACAF Gold Cup knockout rounds. Johnson will join the U.S. for Sunday's match against El Salvador at 1 p.m. PT at M&T Bank Stadium in Baltimore.
Johnson, 29, has 53 caps and 15 goals for the United States. He most recently scored for the U.S. in a 2-0 win over Panama in World Cup Qualifying on June 11 in Seattle. Johnson's last Gold Cup appearance came in 2007.
Johnson will miss Seattle's match against the Colorado Rapids on Saturday, and could miss the match against Chivas USA should the U.S. make the final on July 28.
The U.S. finished atop Group C with wins over Costa Rica, Cuba and Belize to advance to the quarterfinals. In the midst of a record eight-match winning streak, the U.S. is vying for a fifth CONCACAF Gold Cup championship and first since 2007. The champion will qualify for a playoff match against the champion of the 2015 CONCACAF Gold Cup to decide which country will represent CONCACAF in the 2017 FIFA Confederations Cup.
Sounders FC hosts the Colorado Rapids on Saturday. Kickoff is set for 1 p.m. PT on the Xbox Pitch at CenturyLink Field.
And here's the word from MLSsoccer.com. And below, the news from CONCACAF:
The Confederation of North, Central American and Caribbean Association Football (CONCACAF) announced today the names of the players added to the rosters of teams participating in the knockout phase of the 2013 CONCACAF Gold Cup, in line with the tournament regulations changes communicated this past April. Under Section XIII, clause 7 of the competition’s regulations, teams qualifying for the Quarterfinal Phase will be permitted to amend their twenty-three (23) player rosters and replace up to four (4) players from their provisional list of thirty-five (35) players at least twenty-four (24) hours following the completion of the First Round of the Final Phase. The Gold Cup roster modifications are as follows: HONDURAS IN: Erick Norales (DOB: 11-Feb-85; Pos.: Defender; Club: Marathon; Jersey No.: 24) OUT: Johnny Palacios (DOB: 20-Dec-86; Pos.: Defender; Club: Olimpia; Jersey No.: 4) MEXICO IN: Jose Maria Cardenas (DOB: 2-Apr-85; Pos.: Midfielder; Club: Morelia; Jersey No.: 24) OUT: Darvin Chavez (DOB: 21-Nov-89; Pos.: Midfielder; Club: Monterrey; Jersey No.: 5) TRINIDAD & TOBAGO IN: Kevan George (DOB: 30-Jan-90; Pos.: Midfielder; Club: Columbus Crew; Jersey No.: 27) OUT: Khaleem Hyland (DOB: 6-May-89; Pos.: Midfielder; Club: Racing Genk; Jersey No.: 8) UNITED STATES IN: Omar Gonzalez (DOB: 11-Oct-88; Pos.: Defender; Club: LA Galaxy; Jersey No.: 3) OUT: Corey Ashe (DOB: 14-Mar-86; Pos.: Defender; Club: Houston Dynamo; Jersey No.: 3) IN: Alan Gordon (DOB: 16-Oct-81; Pos.: Forward; Club: San Jose Earthquakes; Jersey No.: 9) OUT: Herculez Gomez (DOB: 6-Apr-82; Pos.: Forward; Club: Club Tijuana; Jersey No.: 9) IN: Eddie Johnson (DOB: 31-Mar-84; Pos.: Forward; Club: Seattle Sounders; Jersey No.: 18) OUT: Jack McInerney (DOB: 5-Aug-92; Pos.: Forward; Club: Philadelphia Union; Jersey No.: 18) IN: Matt Besler (DOB: 11-Feb-87; Pos.: Defender; Club: Sporting Kansas City; Jersey No.: 5) OUT: Oguchi Onyewu (DOB: 13-May-82; Pos.: Defender; Club: Sporting Lisbon; Jersey No. 5) The Georgia Dome in Atlanta, GA, will host the first Quarterfinal doubleheader on Saturday, July 20, with Panama taking on Cuba at 3:30 p.m. ET, followed by an encounter between two-time defending champion Mexico and Trinidad & Tobago at 6:30 p.m. ET. M&T Bank Stadium, in Baltimore, MD, will stage the second Quarterfinal doubleheader on Sunday, July 21, starting at 4:00 p.m. ET, when the United States meets El Salvador. At 7:00 p.m. ET, Honduras squares off against Costa Rica.