Jon Jay has been pretty successful as a leadoff hitter this year, and for Game 3 he's back in that spot:
Joe Maddon is playing a hunch here, I think, with Ben Zobrist playing second base and hitting fifth. The last time Max Scherzer faced the Cubs at Wrigley Field, Zobrist hit two homers off him.
Obviously, past performance does not guarantee future results, but Joe often plays matchups and he loves Zobrist, so let's hope Zobrist has one of his better days. I'd assume that Javier Baez will be in the game late for defense, as will Albert Almora Jr.