Liverpool boss Brendan Rodgers insists he will not spend more money in the transfer market just "for the sake of it".
Simon Mignolet, Kolo Toure, Iago Aspas and Luis Alberto have all arrived at Anfield this summer but Rodgers has stopped short of admitting that more players are about to join.
"They have to be of the right quality, that's the bottom line," Rodgers told LFC TV.
"We've got money to spend on getting that quality in but if it's not available I won't waste it for the sake of bringing a player in.
"We're really working hard to bring in the type of profile that can really help us push on."
Rodgers praised winger Raheem Sterling, who faded out of the Liverpool side after an eye-catching start to last season, for his reinvigorated displays in pre-season.
"He has reminded me of what he was last summer, but he has got a little bit more personality now he has had a year's experience. At 18, he has looked really good."
Mignolet's arrival from Sunderland heralded the departure to Napoli on loan of Pepe Reina, but Rodgers feels his Belgian signing has the ability to develop into one of the best in his trade.
"Simon Mignolet has been first-class. He has shown that he is one of the top young goalkeepers in European football," he said.
"I think he will prove over the next coming years at Liverpool that he is a top goalkeeper."