Alan Knill told the clubs official website "I have told him to go there and score plenty of goals to get his full confidence back again. If he can do that then we will benefit when he returns to us again."
The 24-year-old's move to the County Ground has been funded largely by Swindons supporters trust, TrustSTFC Red Army Fund. "This is a great example of fans and the club working to achieve what we all want - success on the pitch," director Bob Holt told Town's website.
It is rumoured that Swindon are playing all of Proctors wages.