Sunderland boss Steve Bruce says he will not be overly disappointed if he is unable to capture any more transfer targets before the window closes.
Bruce has brought in 10 new faces to the Stadium of Light this summer, including former Manchester United duo John O'Shea and Wes Brown.
Bruce told BBC Radio Newcastle: "You can never say never, we'll keep trying and we'll keep plugging away.
"But I'm very, very pleased - I'm delighted with what we've done."
The Black Cats started their pre-season campaign on Wednesday with a 2-1 win over York City at Bootham Crescent, Phil Bardsley and Oumare Tounkara scoring first-half goals for the visitors - Jamie Reed grabbing a second-half penalty for York.
And having already landed two players from his former club, Bruce is now hoping to make Darron Gibson the third player to arrive from Manchester United, while Wigan's Charles N'Zogbia has also been linked with a move to the Stadium of Light.
"A manager's job is always to keep knocking on the door - that's my job," he continued.
"We've bought in something like eight or nine players which is a huge amount and my job is to keep asking for more - believe me I'll do it."
"There's still a bit to go [until the transfer window closes] and it's important because there's still three of four players that need to go out as well and we'll see what happens after that."