Bantams duo Adam Thompson and Shay McCartan were both unused substitutes in Northern Ireland's victory over San Marino this Friday evening.
Second half goals from Josh Magennis (2) and a Steven Davis penalty secured a 3-0 win for Northern Ireland over the european minnows.
The victory - Northern Ireland's fourth in a row - means they now need just a point at home to Czech Republic on Monday evening to secure the runners-up spot in Group C.
Group runners-up in european qualifying for the World Cup 2018 will claim a play-off place a chance to earn a spot in Russia next summer.
Thompson and McCartan's involvement in the Northern Ireland squad mean they will be unavailable to City for Saturday's Sky Bet League One match with Bristol Rovers.
The pair are expected to be back training with City in the latter stages of next week, however, in time for the trip to Peterborough United (Saturday 9 September 2017).