Alonso, 26, will be playing in the second all-star match of his four-year career. Johnson, 28, was selected to his third all-star match, his first with the Sounders and first since returning to the United States' most competitive league.
Alonso, a native of Cuba, officially became an American citizen last month. 2012 has been an exciting year for him for this reason and because of his growth as a player.
Always solid since the Sounders joined MLS in 2009, Alonso has been having the best season of his career so far. The holding midfielder has appeared in 15 matches this season and has held opponents to one goal per game, currently second in MLS.
Alonso leads the Sounders with 702 completed passes and an 81.4 completed passing percentage.
Eddie Johnson, an eight-year MLS veteran, returned to MLS after several seasons in Europe. He signed with MLS in February and was selected by the Montreal Impact by allocation process before being traded to the Sounders for Mike Fucito and Lamar Neagle.
Johnson has played well with the Sounders. He currently leads the team with eight goals in 16 matches played.
Alonso and Johnson will represent the Sounders as substitutes when they play visiting Chelsea on July 25 at PPL Park in Philadelphia.