The Saudi club's full-back Joao Cancelo is a Portugal international and midfielder Ruben Neves was a team-mate of Jota with both the Portugal national team and at Premier League club Wolverhampton Wanderers.
The 28-year-old Jota died alongside his younger brother Andre after their vehicle veered off a motorway in northern Spain before bursting into flames on Thursday.
"We all know it's a sad day because of what happened to Diogo and Andre, unfortunately, these are things that shouldn't happen, which happened," said the Italian.
"As we are all aware, we have two Portuguese players, Ruben Neves and Cancelo, who were very close to the guys. Clearly today was a difficult day for everyone. We tried to work but clearly, the atmosphere today was not the same as other days. It was a tragedy," he added.
Al-Hilal left-back Moteb Al Alharbi said the team had tried to be supportive to the Portuguese pair.
"From the moment we woke up today we were shocked by the news. They are team-mates of his and we all felt the sadness but we were all around them. I also believe they will be ready although they have this shocking news," he said.
“They were not at their best emotionally but I believe they will be focused for the game," added Saudi winger Khalid Alghannam.
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