Salah was left on the bench for the 2-0 quarterfinal first-leg defeat, but took part in the post-match warm-down.
Watching on was Pearce, who said on talkSPORT: "I'm also watching down here Mo Salah doing his running as well.
"He's at the front of the running and sometimes this gets unnoticed.
"People say oh his attitude stunk when he come off. He done this, he done that.
"If ever there's a time where a players attitude is going to stink, it's Mo Salah with six or seven games to go on his Liverpool career not being brought on when they need a goal.
"He's got every opportunity for his attitude to stink and he's out there doing the running with the team the box to box work that they do after games.
"So you've got to commend him for that. I know it's his job. I understand that."
Ex-Liverpool captain Gerrard also said: "Credit to him, he's just stayed behind and done extra running.
"If there wasn't a midweek game Wednesday probably would be your big session so in his mind he's already thinking of Fulham on Saturday which shows the pro and mentality that you're dealing with."