Ravenhill has been sidelined since early August with a knee injury sustained at Guiseley, while Jones was put out of action after suffering ankle ligament damage on the eve of City's League 2 opener at Gillingham.
Parkinson will look to feature Ravenhill in Wednesday's reserve fixture at Port Vale, with the Bantams boss also expecting Jones to make a return to training at some point next week.
Parkinson said: "Ricky has done some training this week, he's looking really good.
"There's a reserve game at Port Vale next Wednesday which Ricky will now be involved in if all continues to go well for him.
"Ritchie is just about ready to come back into training. He's done a lot of work out on the training pitch with Matt Barras (Head Physio) recently.
"Both Ritchie and Ricky will be two great additions when they come back into the squad."