Hanson has a slight problem with his calf, Morais has mentioned a minor knee issue, while Reid has some tightness in his groin.
Following last Saturday's win over Southend United, City have already secured their spot in the end-of-season Play-Offs but Parkinson insists his side will still be going all out for victory at the weekend.
Doubts to the likes of Hanson, Morais and Reid may see the Bantams name a changed side from the eleven that began at Roots Hall but Parkinson is adamant that City will still be selecting as strong a team as they can at Valley Parade.
Parkinson said: "Hanson took a whack to his calf. It is not a strain otherwise we would be ruling him out so we will just monitor him.
"Filipe has got a small problem with his knee but it is not related to his old cruciate injury from before.
"Reidy also has a tight groin. All three injuries are nothing major - just the sort of thing you would expect during the season - but we won't be picking anyone we don't think can come out of the traps flying come Sunday.
"We have a lot to play for on Sunday - we will be picking the best team we feel we can for the game.
"Given the bumps and bruises we have in the camp, we would be foolish to risk anyone but, equally, we want to get something from the match.
"Players who get the nod Sunday will be playing to be a part of the Play-Off semi-finals. Those two matches will be massive games that everyone will want to be involved in.
"Whoever starts on Sunday needs to make a statement to us that they want to play in the Play-Offs."