Jamie Carragher believes Liverpool should have added to their squad in January, and feels rivals have better quality from the bench.
At the turn of the year, everything looked rosy at Anfield, with Liverpool looking likely to be one of Chelsea's main challengers for the title.
However, since then, it has all gone wrong - the Reds have won just once against League Two side Plymouth Argyle, at the second attempt in the FA Cup, in 2017.
And Carragher believes that a stretched squad has been unable to cope, insisting it was clear additions were necessary.
"Liverpool don't have the squad to match the other teams and are in a major fight for the top four," Carragher told Sky Sports. "For how great everything was going a few months ago, it shows how quickly everything can just unravel.
"A major disappointment, whether it was down to the manager or the board, was not getting any reinforcements in in January. The players are there. I am not saying panic buy.
"At this moment, there are lots of problems, defensively and in attack, but I am talking about in terms of numbers, Liverpool needed something.
"If you look at Liverpool's bench, they haven't got anything like what Manchester United have got, City have got - these are the teams they are trying to compete with.
"The fact that they haven't reinforced from a position of strength - where they were in the league as the best challengers for Chelsea - has meant they have fallen away.
If you look at Liverpool's bench, they haven't got anything like what Manchester United have got, City have got - these are the teams they are trying to compete with.
"Certain players have been superb all season. You can't expect the likes of Adam Lallana, Roberto Firmino and Philippe Coutinho to keep up their levels, they need to come out of the team, not dropped, but just taken out for a couple of weeks to freshen them up, but there isn't the players on the bench to do that.
"Other sides have got that quality in reserve that Liverpool haven't."
Gary Neville felt that Liverpool's high octane style of play couldn't last when their schedule became busier, but believes all is not lost for the Reds yet.
"Liverpool had a period where they could pick the same side, they had that week to prepare," Neville said. "The minute that that squad hit three games a week, with the way that they play, was always going to hurt them. You cannot play that way three times a week.
"When you are leaving six players back at base, it causes disruption, it disrupts the squad and the squad isn't good enough.
"Liverpool will get stronger as the season goes on. Now they are out of the cups, they are back to that period where they will have a week between games, and that is when they get can get their energy up and become devastating.
"Next season, when they potentially get back into Europe, they will have to strengthen the squad."