Firmino, who left Liverpool last summer after a trophy-laden eight-year spell at Anfield, said he played the role of "firefighter" between the pair when they made up one of Europe's most devastating attacking partnerships -- seen most publicly when Mane fumed on the bench against Burnley in 2019 shortly after Salah failed to pass him the ball for an easy tap in.
"I knew those guys very well, maybe better than anyone," Firmino wrote in his book, "Sí Señor: My Liverpool Years." "It was me out there on the field, right in the middle of them. I saw first-hand the looks, the grimaces, the body language, the dissatisfaction when one was mad at the other. I could feel it. I was the link between them in our attacking play and the firefighter in those moments.
"For many, that disagreement [against Burnley in August 2019] between Sadio and Mo was the first; for some, the first and last. But I knew it had been brewing since the previous season, 2018-19. My instinct and my duty was to defuse the situation between them. Pour water on the fire - never petrol."
Mane left Liverpool in 2022 to join Bayern Munich but departed a year later to join Cristiano Ronaldo at Saudi Pro League side Al Nassr. Firmino also moved to Saudi Arabia, joining Al Ahli as a free agent.
Firmino continued: "They were never best friends; each kept himself to himself. It was rare to see the two of them talking and I'm not sure if that had to do with the Egypt-Senegal rivalry in African competitions. I truly don't know. But they also never stopped talking, never severed ties. They always acted with the utmost professionalism.
"I never took sides. That's why they love me: I always passed the ball to both; my preference was for the team's victory. Many focus on what I brought to the attacking trio in tactical terms, but perhaps just as important was the human element: my role as peacemaker, unifier. If I didn't do that, it would be nothing but storms between the two of them on the field.
"Maybe that's why I was the one most often substituted by Klopp. The three of us had very different personalities and the Boss knew I wouldn't throw a bottle to the ground or anything like that. If I was bothered, I'd talk to him privately afterwards. When a substitution was needed, it was easier to take Bobby off than to upset either of the other two.
"Everyone, including the other players, knew that's how it worked. It was the worst-kept secret in Liverpool - naturally, no one ever asked what I thought or how I felt. That's just my nature; the team comes first. The Boss knew it."