Moyes has already had two bids rejected for the player and Barcelona officials have once again confirmed Fabregas is going nowhere.
United had been of the belief Fabregas was open to the idea of moving back to the Premier League. However, even if the Arsenal skipper is not landed, Moyes is sure he will catch someone.
"I couldn't tell you if there will be another bid," he said. "Obviously we will take stock of it and consider what we are going to do next.
"But what we have here is a really good squad of players already. You mustn't forget about the quality that is already here at Manchester United.
"Undoubtedly we are hoping to add to it. I am quite confident we will do, certainly before the window shuts."
Given how long the situation has rumbled on for, and that executive vice-chairman Ed Woodward flew home on July 18 on "urgent transfer business", it could be argued it will be an embarrassment for United if Fabregas does not come.
"I never at any time said I knew we would get him," said Moyes. "I just said we had made offers. They have been rejected. We will take stock from there and decide where we go from there."