Liverpool boss Andoni Iraola says it will be a "special" experience to go up against a Villarreal side managed by longtime friend Inigo Perez when the teams meet in the Champions League at Anfield on Tuesday.
The two Spaniards first knew each other as young players making their way at Athletic Bilbao before Iraola recruited Perez as his assistant coach when in charge of Madrid club Rayo Vallecano.
"For me it is a special game because Inigo is my friend," Iraola told a pre-match press conference at Anfield on Monday.
"We know each other since the academy years in Athletic Club, we played with each other in the first team. As soon as he retired, I was quick enough to grab him to help as an assistant. We've been through a lot of things together.
"It is a privilege for me to face him in a Champions League game. He knows me very well, he knows everything. It is a team that I follow, I know the players and it is going to be a little bit strange but in a good way."
Iraola, asked if he had spoken to Perez lately, said Tuesday's game had put a temporary restriction on their friendship.
"When these things happen (facing each other in a match), it is not good for relationships," the 44-year-old Iraola explained.
"I talk to him a lot, but when you know you are going to face each other, you stop talking because you leave the distance, you don't want to... Lately, it is probably the moment we have talked less.
"We normally call time to talk about La Liga, the Premier League, about football, other stuff, about our families. But now when the game gets closer, we haven't been in touch."
Iraola is in his first season in charge of Liverpool, having arrived at Anfield from Premier League rivals Bournemouth -- where he tried to bring Perez only for his friend to be denied a work permit by British authorities.
"We tried to take him to England, he was here but he couldn't work," said Iraola. "He didn't receive the work permit. We tried to do everything to convince the panel. I complained in the moment because I came with just two guys, but it has worked well for him also.
"Now he is coaching in the Champions League with Villarreal and I am so, so happy for him."