Phil and Gary Neville believe Liverpool need to make at least five signings if they are to compete with their rivals this season.
Jurgen Klopp's side finished fourth in the Premier League last season, meaning they will play in the group stage of the Champions League again this term so long as they overcome a two-legged play-off next month.
And former Manchester United and Everton defender Phil Neville says they need to boost their squad depth if they are to cope with the increased number of games they will face next season.
Speaking at last week's launch of Soccer Saturday Super 6's sponsorship of Salford City FC, he said: "I think they need numbers.
"The problems they had last season were around Christmas time or January and February when they had multiple injuries in their squad.
"The squad didn't have enough depth to cope with all their injuries.
"I think with their Champions League qualification now with the FA Cup, the League Cup and the League, they are going to need five or six more players to thicken up the squad and they're going to need quality to improve the starting XI.
"I think there was a period just before Christmas, maybe in November, when you thought 'Liverpool could win the league this year.'"
They [Liverpool] are going to need five or six more players to thicken up the squad
Liverpool signed Loris Karius from Mainz last summer, but Simon Mignolet re-established himself as the club's number one goalkeeper and played 28 league games last season.
However, Phil Neville does not believe he is good enough to play for a title-winning team and urged Klopp to seek yet another 'keeper.
"In terms of the positions in which Liverpool need strengthening, I think the goalkeeping situation is always a healthy debate," he added.
"With Mignolet there, is he a goalkeeper who is going to win you the league? I don't think so and maybe that's a position they have to strengthen.
"But I think squad depth is a problem Liverpool have, more than squad quality."
Sky Sports analyst Gary Neville agrees a shot stopper should be on Klopp's shopping list this summer - but he also feels the German must work to improve his defensive options overall.
"I think they need centre backs," he said.
"And a left back. I think James Milner did a brilliant job last season, but to continue to think he can keep playing there…
"I think they need to sort out the defence and the goalkeeper and although I do like Emre Can, potentially a holding midfield player, depending on how Jordan Henderson is."