The two sides played out a thrilling 3-3 draw at Ashton Gate on January 3, a result which left Adams full of respect for the Robins.
His side head into the match having not won any of their last seven games, and he is without at least five first-team regulars through injury.
Adams wants his side to bounce back from this weekend's loss to Crystal Palace in the league, but has told his players they will have to fight hard.
"Saturday was massively disappointing, but the one thing we have got to do is come out fighting because the match has all the makings up an upset," he warned.
"They certainly showed enough in the first game to suggest that they are far from out of the competition."
Bristol City will be without new signing Brian Wilson as he is cup-tied, having played for former club Cheltenham in their first round loss to Scunthorpe.
Captain Louis Carey has shaken off an ankle injury in order to line up against his former club.