The Egypt star was speaking after scoring in victory at Manchester United on Sunday.
"I was coming to the game, I was saying, 'look, it could be the last time'," he told Sky Sports.
"Nobody in the club talked to me yet about contracts so I was just like, 'OK, I play my last season and see at the end of the season'.
"I feel I am free to play football – we will see what happens next year.”
On the win, Salah said: "A great result.
"Everyone knows the derby is important for the fans and the city. We need to carry on and if you want to fight for the league you have to win each game.
"I managed to be involved in three so I am happy about that. The manager likes us to press high and there was a couple of mistakes and we managed to use them - it was part of the plan.
"With Jurgen we were always like this to get the ball as high as possible. Quite similar from seven years ago, the manager has his own system and we try to adapt that."
Liverpool boss Arne Slot also said of Salah: "It's a lot of 'if'. At this moment he is one of ours and I am really happy with him being one of ours and he played really well.
"I don't talk about contracts from players but I can talk for hours about how Mo played today."