The Egyptian star, out of contract at the end of the season, has repeatedly expressed his desire to stay but acknowledges this could be his final campaign at Anfield.
With 30 goals and 21 assists in just 38 games, Salah is enjoying the most prolific season of his Liverpool career.
“Mo has had some outstanding seasons here at Liverpool and we hope he can continue that for a long period of time,” he said.
“But to do that, first he has to extend his contract, of course.
“You can look at it in both ways. You can say the better he does, the more expensive he might become. And if he did really worse, we would have second thoughts if we want to extend his contract.
“For everyone it is the best that he brings in the performances he does now. Maybe only for the one who has to pay him it is not the best!
“For everyone else it is the best because if you want to play at this club, you need to be at his level otherwise you are probably almost useless to play at this club because we only need players that are at the top of their game.
“Because this is one of the best, or the best, club in the world to play for. He needs to have these performances for him to play here and hopefully to extend here.”