After meeting with Ravenhill at the back end of last week, Parkinson has agreed that the time is right for the midfielder to find himself some first team football elsewhere.
No loan deal has been reached with another club as of yet for Ravenhill's services, but Parkinson will not stand in the midfielder's way if something suitable were to come along.
Ravenhill, who has failed to make the bench for City's last two fixtures, has featured only three times in the league for Parkinson's men this season - all as a substitute.
The 32 year-old's two starting appearances this campaign have come in the club's Capital One Cup tie at Huddersfield Town and their Johnstone's Paint Trophy clash with Hartlepool United.
Parkinson explained: "Ricky (Ravenhill) has expressed a desire to go out on loan.
"He feels he is at an age where he needs to be playing regular first team football, and I agree with him.
"I feel it is the right time for Ricky to move on and get some football. That is why Matthew Bates coming in helps us. He can play in midfield as well as defence, so he leaves us with four central midfielders still to choose from.
"Ricky is a tremendous professional and he loves playing for Bradford City, but his contract is up at the end of the season and he is aware that he needs to be playing to earn himself another one.
"This is Ricky's decision - he wants to go out on loan. I would be more than happy to keep him here because he is a good squad player.
"When his name lands on managers' desks, I am sure there will be no shortage of takers.
"I think we will have a number of enquiries for him, so I don't suspect Ricky will be waiting too long to go out on loan."