Liverpool boss Brendan Rodgers wants reinforcements in the summer to sustain a top four challenge next season.
"I just think we need a bit more depth and a bit more quality," he told Sky Sports.
"The players this year have done very well. I have asked everything of them and, in the main, they have done very well.
"The majority of the time, there have not been too many performances where I have been really disappointed."
"The club respect where we need to strengthen and where we need to improve," said Rodgers.
"We have seen from the last window in January, we got our business done early and brought in two outstanding players in Sturridge and Coutinho.
"Hopefully we will have a similar impact in the summer. If we can do that, that will make me really happy with the group going forward."