consider the high altitude as a factor in the world cup. another
factor to consider is the fatigue after an exhausting european
league, esp if the teams were in the CL up to the semi's. you can
see already the number of goals scored after 2 matches, 2 goals in
2 matches.
Friendlies will also make players more exhausted. So, those played
for UCL finals/ League should be spared by coach from playing
the friendlies.