Sporting director Lee Congerton has said the focus is on adding quality not quantity to the Sunderland squad during this summer.
The Black Cats have already signed Costel Pantilimon, Jordi Gomez and Billy Jones for the 2014-15 campaign.
However, Phil Bardsley, Jack Colback, Craig Gardner and Carlos Cuellar are among those who have left.
Congerton told BBC Newcastle: "We we do need more players, but it's not so much about quantity, it's about quality."
"I don't want to sign players just for the sake of it. We want to sign players who are established in the Premier League and that is difficult - there is a premium, they are more expensive."
Last summer's transfer dealings under former boss Paolo Di Canio stretched the net far and wide, with 14 arrivals by the beginning of September.
By the end of the campaign new head coach Gus Poyet had added a further four players to the side, but Congerton has warned against a repeat of such activity on Wearside this summer.
Instead, the focus will be on a core of players for the top flight campaign.
"The starting XI is very important," Congerton explained. "We need to have a squad but first of all we need a starting side that can be competitive.
"We need to replace the likes of Ki (Sung-Yeung) and Fabio (Borini) before we're on a level footing.
"We've got a lot of work to do, we're trying our best and working every day.
"Ultimately, hopefully before the season starts we'll have our squad together but given we haven't got vast amounts of money it will probably go to the last moments of the transfer window."