Elected to start for the fourth time, Molina tore a ligament in his right thumb Wednesday. He was scheduled for surgery Friday and is expected to be sidelined for at least eight weeks.
Boston Red Sox manager John Farrell, who will manage the American League All-Stars, announced Friday that Detroit Tigers second baseman Ian Kinsler would replace teammate Victor Martinez, who has been sidelined with an oblique injury, on the active roster.
Kinsler, who will make his fourth All-Star appearance and first with the Tigers, has a .305 batting average with 11 home runs, 50 RBIs and 10 stolen bases on the season.
Information from The Associated Press was used in this report.