Preventing Developers from seeing the 'Estimated Time'

Hello,

We use off site developers. Though we wish to be able to add 'Estimated Time' so we can compare this to what it actually took, we do not want the developers to see this as this will give them insight as to how much time we have in our minds. We prefer to not have them biased by this.

Is there an ability to prevent Developers from seeing Estimated time when they review their new job assignment?