Chelsea supporters will remember that shock defeat at the hands of Bradford last season and Scunthorpe are 14/1 (BetVictor) to do the same at Stamford Bridge.
The League One team will be backed by thousands of fans, with William Hill offering 5/1 that the game ends all square which would lead to a replay at Glanford Park.
The Blues are massive favourites at 2/9 (Paddy Power) to book their place in the next round of the competition, with Diego Costa a best price 3/1 (bet365) to break the deadlock as Chelsea look to build up a head of steam
Our best bet of the match is for Chelsea to overcome Ladbrokes two goal handicap at 11/8
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