Manchester United are favourites for the 18 year-old midfielder.
"Nick is still with us, but I am sure talks are still ongoing with his agent and clubs," Davis told Crewe's official website.
"These things take time and rightly so because all parties have to be satisfied with any deal.
"I still envisage him leaving us this summer, but if it doesn't happen then we would welcome him back for pre-season.
"We'll see what happens this week because obviously I would like to know as soon as possible if we are moving forward without him or not."
The move away from Crewe would be final for Powell, with Davis ruling out the prospect of an immediate loan return being part of any transfer deal.
He added: "One thing I can confirm is that he won't be coming back here on loan.
"That wouldn't be part of it because we want to bring in a replacement of our own and give our own players, such as (fellow England Under-18 forward) Max Clayton, a chance."