The Robins are unbeaten in two visits to the Ricoh Arena scoring five goals and conceding none and the City manager knows that the Sky Blues will be in for a tough game.
Said Chris Colemn to the Ct: "This will be a tough, tough game - maybe our biggest test yet.
"Bristol will come here and make us work hard. They had a great season last year and they're a good team - very well organised at the back.
"They're tricky on the wings and they've got big Dele Adebola who we know very well from his days here.
"We have got to go into the match with a tough mentality, take the game to Bristol City and be prepared for a hard 90 minutes."