Machi was ejected after the inning ended on Nick Punto's double-play grounder.
Center fielder Angel Pagan was the other Giants player to be ejected from a game this year, receiving the thumb in an April 21 game at Colorado.
Chris Haft is a reporter for MLB.com. Read his blog, Haft-Baked Ideas, and follow him on Twitter at @sfgiantsbeat. Ryan Hood is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.