Paul Merson insists that Jurgen Klopp remains an elite manager, but believes the Liverpool boss is "getting tired" by the current situation at Anfield.
And Merson has warned owners Fenway Sports Group that they need to back German in the January transfer window.
Liverpool have endured a dire season so far in the Premier League, winning just four games and losing four others. They are now 15 points adrift of leaders Arsenal, with their hopes of winning the Premier League title all but extinguished. Klopp has been in his post for seven years, winning one league title, the Champions League, the FA Cup and the Carabao Cup.
While Merson is confident Klopp can turn things around, the former Arsenal star insisted the Liverpool board have to step up and help.
"Will Klopp be thinking he's taken Liverpool as far as he can? I'm not sure, but one thing I am certain of is that it will ultimately be his decision. Liverpool have to keep him but whenever the time comes to make a decision, it will be his," Merson told Sky Sports.
"Klopp is an elite manager, he's not in the job to finish fourth in the league, for those kind of managers that is not success. Klopp will want change. I don't think he has been backed that much, yes, they spent £85m on Darwin Nunez but that was one player, they need a few more if they are going to get back to where they were.
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"What Klopp has done at Liverpool, winning the league after all those years, is hard work. He has worked his socks off, he kicks every ball on the touchline. Just like players, Klopp will be getting tired, and you get more tired when you are not winning games compared to when you are winning.
"You have got to remember that the majority of this group of players have been ripping it up for the last six years.
"That will eventually take its toll on any player, I don't care who you are. Liverpool aren't lazy, they are a hard-working team who work their socks off and, all of sudden, all of that hard work is catching up with them."
Liverpool have suffered successive defeats to Nottingham Forest and Leeds United, with a challenging trip to Tottenham coming on Sunday. And Merson believes they are in "major trouble" amid their dreadful form.
"To put in a performance like Liverpool did against Manchester City and then follow it up with defeats against Nottingham Forest and Leeds is inexcusable. Only the players can tell you what was different on those occasions," he added. "After the performance against City we thought, here we go. With Forest and Leeds up next, it was an opportunity for Liverpool to take off. But now, they are in major trouble. Jurgen Klopp must be pulling his hair out.
"Liverpool are losing their fear factor, and this season is already worse than the season they defended the title. It's completely different now, Liverpool know that. They have that experience under their belts and there is no excuse for their performances this season.
"Liverpool's prospects have all changed since the start of the season. They are not Premier League title contenders anymore, they have to get into the top four and secure Champions League football, it's as simple as that."
