Striker Jozy Altidore says Sunderland are in "transition" after their summer recruitment and still need to integrate the new arrivals into the squad.
Nine new signings were made, including Jack Rodwell and Jordi Gomez.
The Wearsiders have drawn two and lost one of their first three Premier League games this season, going down 1-0 at QPR in their last outing.
"It's a transition and these are the hard times especially for fans," Altidore, 24, told BBC Newcastle.
"They want to see the team be successful right now which is difficult."
|Jozy's big night|
|Jozy Altidore captained the United States in their 1-0 win over the Czech Republic in Prague on 3 September"It was amazing to captain a country like that, a massive country. A lot of eyes on me but it was a really special moment for me too."|
Altidore, who joined Sunderland from AZ Alkmaar last season and had a mixed first campaign at the Stadium of Light, has first-hand experience of the pressures players face at a new club.
He sees the success of Swansea, one of Gomez's former clubs, as an example of how a system can be developed to allow players to slot in promptly.
"Because they play how they play, whatever player comes in, sooner rather than later, within a couple of weeks, they fit right in to the system," the USA international said.
"We have to try to emulate that in that when we get new players they can come right in and be successful."