To be honest I think its mostly from embarassment. The response of the players towards Malcom after the goal was not normal. It was like they were standing up against what they felt was a unnormal situation and a sense of injustice.
Messi had also done one of his little subtle moves to voice his displeasure by publically talking positively of Malcom, now after the goal the players spoke with their public support of Malcom with his goal celebration.
Malcom was classy as always, no vent of frustration, just an emotional burst showing that he is going to prove his class and that he really wants to succeed at his dream club.
Valverde must of been overjoyed at the goal and the instant impact, but with the players reaction it instantly reflected poorly on him and he had egg on his face.
How could a player like Malcom be ghosted out of sporting reasons? He come on and showed acceleration, first touch, intelligence, hustle, hold-up, awareness, finishing, timing all in 10 minutes. He got one goal and almost assisted a second.
This wasn't a case of a player being in the right place at the right time to turn the match but not necessarily having the talent to consistently perform here like Maxi Lopez versus Chelsea or Sandro Ramirez versus Villarreal. This was a show of genuine talent waiting to explode that for some reason oblivious to many, had been subdued.
Now the tables turn in Malcoms favour. The timing of the injuries (Coutinho, Messi and Dembele less than 100%) should guarantee him a start this weekend. The Camp Nou will be fully behind him and thanks to the way his start has been conducted he could turn into a cult crowd hero. Lets hope Valverde gives him all the chances to succeed, and by that I mean starting on the right and not being the first sub off the pitch