The 2-1 reversal at the hands of bottom-of-the-league Colchester at the Coral Windows Stadium on Tuesday evening - City's first defeat in five games - denied them the chance to move into to League 1's top six.
Defeats for other Play-Off contenders on the same evening, however, left things well and truly wide-open still at the top end of the table with thirteen games to go in the Bantams' regular league season.
The City chief now wants see his side react positively from the disappointment of the Colchester defeat when they travel to Gigg Lane at the weekend.
Parkinson said: "This is a tough business that we are in but we have to make sure it (Tuesday's defeat) doesn't knock us too much and that we are ready for Saturday.
"We have dust ourselves down for the (Bury) game and look for a reaction. We know we must do better.
"It is the nature of football really. We had a high last weekend at Blackpool and now we've suffered a low on Tuesday.
"We've had been on a good run of form recently and we have to make sure we can get back to where we were before.
"Other teams have lost recent games so everything is still to play for."