The talismanic midfielder has been the subject of two failed bids from Derby, who continue to be linked with another move ahead of Tuesday’s 6pm summer window deadline.
Powell is anxious for that to pass with Butterfield still a Town player, while insisting that the 25-year-old remains fully focused on matters at Huddersfield.
Powell said: “We have turned down several bids from Derby and that shows we are trying to stay strong on it.
“I understand how football works and Jacob does.
“We can’t stop them picking up the phone and coming back, but we do have a valuation and a price for every player.
“We do have that for Jacob and if it is not met then my chairman says no. It’s as simple as that.
“Recent speculation has been tough for him, but he has played, which I think is testament to him and maybe my relationship with him. Until he is told otherwise, I know he will continue to do that.
“Of course, I want Tuesday to come at 6pm and for it (Butterfield interest) to be gone and it doesn’t happen.
“I have got to say we have been fair in our behaviour and correct in turning down the bids that have come in.
“I just want Jacob – and I am sure all the fans will agree – to continue in the blue and white of Huddersfield.”
On the incoming front, Powell last night completed the capture of Middlesbrough winger Mustapha Carayol on a season-long loan.
He also signed Wigan Athletic midfielder Emyr Huws, again on loan, with young Town striker Jordy Hiwula making the opposite move.