The former defender believes his old side need ready-made stars, not youngsters, for next season.
The Reds had a busy summer last time around; spending the money generated from the sale of Luis Suarez on several youngsters - including Lazar Markovic and Alberto Moreno, among others.
They also spent large sums on Adam Lallana, Dejan Lovren and Mario Balotelli, although only the first of that trio have done anything of note in their first season at Anfield.
Now, Carragher says they must sign players who are first-team ready for next season.
“It's important Liverpool buy players ready to go straight into the first team,” he said.
“There's no doubt some of last summer's signings took a bit of time to settle, and so you will be looking for ones this summer to come in straight away.”
The former defender turned pundit also believes that Italian forward Balotelli is unlikely to have a future at the club beyond this summer.
When the former Manchester City man was signed from AC Milan it was arguably a big gamble for manager Brendan Rodgers, one that has failed as he has struggled to perform in a Liverpool shirt.
Elsewhere, he believes that fellow forwards Fabio Borini and Rickie Lambert may also be on their way out of the club, if the money of offer is right.
“I don't see Mario at the club next season,” he added.
“Now that he has been at so many clubs the problem is you don't know where you can see him go. Not just Balotelli, Borini and Lambert as well I think will be looked at if the money was right.”