Sporting Kansas City's leading scorer steps in for the Toronto FC striker, who joins Omar Gonzalez, Chad Marshall and Robbie Keane as a withdrawal.
The Sporting Kansas City striker was called in Sunday to replace Toronto FC's Jermain Defoe, who missed his side's 2-0 win against Montreal on Saturday because of a groin injury.
Dwyer is tied for second in MLS with 14 goals but was initially overlooked as Thierry Henry, Landon Donovan, Clint Dempsey, Obafemi Martins, Robbie Keane, Bradley Wright-Phillips and Erick Torres made the squad over him.
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Keane and defenders Omar Gonzalez and Chad Marshall withdrew from the team Saturday, with defender-midfielder Maurice Edu, center back Bobby Boswell and right back Sean Franklin stepping in.
The MLS All-Stars face Bayern Munich on Wednesday in Portland, Oregon.