I brought my son to see Argentina play (I think against Ecuador) several years ago in a friendly in the US. There was a blizzard-like snowstorm, and they were all out there in shorts, making slide tackles. I was very close to Mascherano when he came out for the second half and he had a splint on his finger. He just put it all out there, without regards to the weather and that it was a friendly. Soccer players, maybe particularly of the South American variety, are tough (I guess Brazil divers are maybe an exception).
Friendlies tend to be very competitive because the players are fighting for spots on the teams for the big tournaments.
It’s like the NFL Exhibition games, guys are fighting for roster spots and give their all.