Graeme Souness has delivered a damning verdict on Mohamed Salah, suggesting that the Egyptian King has "fallen off a cliff" and is the single biggest reason Liverpool have struggled to defend their Premier League title. The former Reds captain also claimed that Salah's best years are behind him, before calling for the club to sell him at the end of the season.Souness has seemingly seen enough this season to make up his mind. The former midfielder was at the Community Shield back in August and left with doubts, hoping a handful of games would help Salah find his feet. Fast forward to March, and his opinion has not changed."What happens, in my opinion and in my experience, is your career happens one of two ways. When you get to that sort of 33-34 age area, it's either falling off a cliff, or it's a slow decline. I think Salah is the former," Souness told the Daily Mail. "I went to see the very first game of the season, the Community Shield against Crystal Palace, and I was sitting next to my young son, I said, 'I don't know what's wrong with him?' And then I thought, maybe he needs half a dozen games to get up to speed. But he's never improved."The numbers appear to back him up. Salah has contributed 10 goals and nine assists across all competitions this season. At this stage last campaign, he was sitting at 44 goal contributions. The season before that, 34. His lowest tally in any previous season was 27. This year's total of 19 is by some distance the worst of his Liverpool career.For the former Liverpool man, the problem is not just Salah's individual output, but what his dip in form has done to the rest of the dressing room. "His numbers are way down, and he is the single biggest reason why Liverpool are having an indifferent season. Because within that group of players, there'll be some that are feeling the pain, some are feeling the negativity that's around the place, and they're not responding very well to it. And when you're in that position, you need big players to stand up and be counted. His best is behind him now, there's no doubt about that. The first person to know that is yourself, and it happens to everyone. I don't see the same sparkle. I think if you're looking for the single biggest reason for Liverpool's shaky form, it's because he's not been getting the numbers. He's been for six, seven years the Liverpool go-to man. He has completely changed games when it wasn't going their way. He's a great, a Liverpool great, but his best season is behind him."Unsurprisingly, Souness believes that Liverpool should part ways with Salah at the end of the season, despite the Egyptian still having a contract that runs until 2027. Liverpool's 4-1 aggregate win over Galatasaray to reach the Champions League quarter-finals saw Salah score, but instead of praising last season's Premier League winner, he opted to crucify the opposition. "I thought Galatasaray were exceptionally poor. I expected so much more from them. They didn't believe they could get a result. And Liverpool, okay, you can only beat what's in front of you but Liverpool are not the same team as last year. Wednesday night was a good game for them because the opposition was so weak."Add GOAL.com as a preferred source on Google to see more of our reportingSouness was not done once he had finished with Salah and Liverpool. He has tipped Arsenal to win the league and steal the club's crown, although he did question the methods that have helped them get into their current position. "Arsenal get away with a hell of a lot by crowding goalkeepers and blocking goalkeepers. I love the term 'free-kick guru'. Their guru is all about fouling the goalkeeper. That's as simple as, black and white. To be successful at free kicks you need a really good kicker of the ball, you need people who will attack the ball, and then you throw in the guy who's fouling the goalkeeper. It's not rocket science."Chelsea and Liam Rosenior did not escape from Souness' all-out warfare against the Premier League's elite either. He added: "Chelsea are a group of young men put together with no real direction. I think the manager tries too hard with his terminology. Giving players 'assignments'. If the manager said that to me, I'd have laughed at him in his face. I just think he tries too hard to be a top coach, with his body language and what he says. So no surprises for me, Chelsea going out of the Champions League."Seemingly, the Scotsman has been less than impressed with how the Premier League season has unravelled this season. Whether that is Salah's form, or Arsenal's dark arts, the former Liverpool man clearly thinks this year is one to forget.