Manager Jurgen Klopp picked 22-year-old Trent Alexander-Arnold as captain instead, and Salah responded by scoring a first-minute goal in a 1-1 draw.
"Honestly, I was very disappointed," Salah who scored a first-minute goal in the 1-1 draw with Midtjylland, told Diario AS. "I was expecting to be the captain. But it's the manager's decision. I accept it."
His goals helped fire Liverpool to the Champions League trophy in 2019 and the Premier League, ending a 30-year wait for the club, in 2020.
"I think Madrid and Barcelona are top clubs," he said. "We never know what's going to happen in the future. Right now I'm focused on winning the Premier League and the Champions League again with [Liverpool]."
Salah's contract at Anfield runs until June 2023.
"That's a tough one," he said, when asked how long he would stay. "Right now I can say everything is in the club's hands. Of course I want to break records here, every record at the club, but everything is in the club's hands."
Salah and the Reds were back in action on Sunday, with the Egyptian scoring twice in a 7-0 thrashing of Crystal Palace.
When asked about Salah's comments after the win vs. Palace, Klopp merely laughed and said: "Nothing to say about that on my side."