Strasburg originally was selected to pitch for the National League team, but he came off the disabled list Sunday and won't participate as a precaution.
The Nationals say Strasburg, who is from San Diego, plans to attend the game.
"Max was excited. Never seen a veteran guy as elated as he to be a part of the All-Star Game," Washington manager Dusty Baker said. "I think he's a good representative to show people what a privilege and an honor it is to go."
"Because of Stephen's injury that he just came off of, being on three days' rest, it would have cost him time again with us," Baker said. "So I'm just glad that he's going, especially in his hometown. But there's a lot of risk for Stephen since he just came off the DL, and you don't know how he's going to come through this game tonight. So everybody decided it'd be better that he doesn't start or pitch."
Strasburg is 12-0 with a 2.62 ERA this season. Scherzer is 9-6 with a 3.21 ERA.
Major League Baseball also announced Friday that Toronto Blue Jays outfielder Michael Saunders and San Francisco Giants first baseman Brandon Belt won the final two All-Star roster spots, elected by fans in online balloting.
"This is a proud moment for me and my family," Saunders said. "Everyone knows that Canada takes care of their own. I'm Canadian through and through. Just to feel that support, the best way I can describe, everyone's been asking me, is I feel loved by this country. To see the support they gave me is very humbling."
Saunders joins the American League team, while Belt gets a slot on the NL squad.
"Extremely excited, obviously. It's hard to put into words," Belt said. "I just can't believe that I'm an All-Star this year. It's pretty cool, especially when you step back and think about how many fans voted and how many times they voted, how many messages that I got of how their thumbs were numb. It's pretty overwhelming to think about."
The Associated Press contributed to this report.