Rangers manager Ron Washington picked Farrell to join his staff for the game that will take place on July 12 at Chase Field in Phoenix.
Farrell will be joined by Indians manager Manny Acta, who was also selected by Washington for the coaching staff.
"It's an honor to represent the Blue Jays, to represent the American League," Farrell told reporters on Wednesday afternoon. "It's a special couple of days, and we all know that it has an impact in the postseason.
"I don't know what impact I'll have in the game -- probably very little -- but to be included in it is definitely an honor."
For the National League staff, San Francisco's Bruce Bochy picked D-backs manager Kirk Gibson and Washington skipper Jim Riggleman.
Farrell previously served as a pitching coach for the AL All-Star team at Yankee Stadium in 2008.
The 48-year-old rookie manager has led Toronto to a 21-20 record despite having to deal with players missing a combined 194 days to the disabled list this season.