Keane was largely a bit-part player in his short stay at Anfield, scoring seven goals in 28 games before securing a move back to Tottenham.
And Crouch, who suffered similar treatment before joining Portsmouth last summer, said he felt for the Republic of Ireland striker.
"There are a few similarities between what has happened with Robbie and my own situation. I feel sorry for him," Crouch told The Sun.
"We all know what a great player Robbie is but he didn't get a fair crack of the whip at Liverpool.
"But that is the way Rafa operates and it can be very frustrating because, when I was there, he never really explained why I was not playing.
"There were times when I thought he didn't fancy me but then he'd start me for two or three games on the spin.
"It got to the stage where I gave up second guessing which games I would be playing and which ones I wouldn't.
"The biggest letdown for me was the Champions League final against AC Milan, when Rafa went with one up front and played Dirk Kuyt, as I was desperate to show what I could do on the big stage.
"The Liverpool fans won't care about what Rafa is like as long as they keep winning and you cannot argue with his record but, at the same time, it can be very frustrating."