Simon Grayson admits his transfer plans will be in part affected by who leaves in the coming weeks.
The Black Cats sold Jordan Pickford for £30 million earlier this summer and Vito Mannone earlier this week, but still have a number of major earners on the books.
Debt levels are high but he has said he has a 'realistic' budget and room to manoeuvre in terms of the wage bill.
When it comes to buying players outright, however, more funds may need to be raised before the 47-year-old can make serious inroads.
He said: "It will make it easier if players went out, because there’ll be money to spend in terms of outlay on transfer fees. It doesn’t stop us bringing players in on loan. Paying wages isn’t a problem, it is more maybe the transfer fees to get players on a permanent basis, if players leave then that will be easier."
The Sunderland boss has also hinted that he is in the market for two goalkeepers following Mannone's departure. The Italian left for Reading to leave Mika as the only senior keeper in the squad, though he is still yet to make his competitive debut for the club.
Robbin Ruiter is on trial with the Black Cats and impressed during the 3-2 win over Bradford on Saturday afternoon. Grayson said he would not make a rash decision on the basis of one game.
He did, however, say he is looking for competition for the number one jersey.
Sunderland are tracking Leeds United's Rob Green and are unlikely to face further competition from Middlesbrough after they signed Darren Randolph for £5 million.
They have also been linked with a move for Blackburn Rovers goalkeeper Jason Steele.
Grayson said: "You’ll have to wait and see. We want competition for places. We’ve got two on our books already, but if we got Robbin and maybe another then that clearly adds to the competition."