Wells departed City for West Yorkshire neighbours Huddersfield Town for an undisclosed fee this Friday evening after over two and a half years at the club.
Parkinson admits that Wells was ready for his move away from the Coral Windows Stadium and that he knew for some time that it would be likely the Bermudian would be leaving in the January transfer window.
With Wells now out of the picture for the Bantams, Parkinson has set his sights on replacing him with a striker who has a known track record for finding the goal on a regular basis.
Parkinson said: "It was the right time for him (Nahki Wells) to go. He didn't want to sign a new contract and, in truth, I felt his mind hasn't really been completely focused on us for a while.
"It has been clear to me for a while that Nahki was going to go, I just didn't want to say it publicly beforehand.
"If he was going to go, it was best for us that he went now and not on the last day of the transfer window. That would have left us in trouble in terms of getting new players in.
"Once it was clear that Nahki was going to go, it was up to the chairmen then to maximise the amount of money we got in for him. We can now use that money to try and strengthen the squad.
"I discussed things again with the chairmen Thursday afternoon. We tried to get someone in for this weekend but that didn't happen through no fault of our own. It is very important though that we get a proven goalscorer into the club. That is absolutely vital.
"This Nahki piece of business will only be good for the club if we can get a proven goalscorer in the building.
"We have to get one and we will endeavour to do so."