Real Madrid captain Sergio Ramos understands the whistles directed at Cristiano Ronaldo, but believes fans should be more thoughtful.
The Portugal star netted twice in extra time as the hosts at the Santiago Bernabeu recorded a 6-3 win on aggregate.
Ramos said the demands of Madrid fans meant he could see why Ronaldo was jeered by supporters in the quarter-final second leg.
"I understand the public and Cris," he said. "He is a player who always gives the maximum. He can have good or bad matches like everyone.
"But people should think about it a little more. The Bernabeu has pounced on all the big players because they always ask for a little more.
"It is difficult to succeed here."
Ronaldo became the first player in history to score 100 Champions League goals during his quarter-final heroics.