Liverpool boss Kenny Dalglish insists it was imperative they spent big money this summer and hinted his spending is not yet over.
The Reds boss has splashed out more than £100million on new talent since he returned to Anfield in January.
Dalglish has paid tribute to the club's American owners Fenway, led by John W Henry, for investing.
But with their backline looking anything but solid thus far during pre-season, Dalglish is expected to bring out the cheque book again before the end of August.
Newcastle's Jose Enrique looks firm favourite to come in at left back, whilst Bolton's Gary Cahill and Birmingham's Scott Dann are believed to be topping Dalgish's options in central defence.
"Everyone hopes all their signings will come in and make a huge impact, but we believe we have improved and enhanced the talent we already had here," said Dalglish.
"Spending money does not guarantee you success. (But) I don't know of any football club that has ever had success that has not spent money. So it is necessary.
"But it's even more important to spend it wisely. We've acted responsibly in the transfer market and we've also acted responsibly and respectfully with the owners, who have been fantastically supportive during the window.
"If there is a better owner that is as supportive as John W Henry, then they have done very well for themselves because he's fantastically supportive, a genuinely good fella.
"I never had any doubts (about Henry's credentials), so you need to ask the people who had the doubts."