Odds

Reasoning

Brentford are a Premier League side that opened their league campaign with a 3-0 home win over Tottenham, while Birmingham have only two Championship draws so far and are yet to win. The division gap and early form make Brentford the stronger side, but cup rotation and Birmingham's home draw tendency mean an outright away win is less certain. X2 covers the draw and still backs Brentford not to lose in normal time.