"We're still working hard to bring the right players to the club," Gray told Town's official website.
"In a perfect world you'd have your squad in place for the start of pre-season training, but I don't think that will happen and I'm not too worried about that.
"Things take as long as they take and what's most important is that we get the right people.
"Up front is obviously where we're looking but we haven't ruled out other players as well if the right deals can be done.
"We don't just have one player we're looking at, we have a shortlist of players who we think would be good additions and we're working hard to make things happen."