The result led to Valladolid's supporters' club association demanding the players pay for the away fans' tickets, which was rejected by the club.
Anuar has now written to fans in a public letter to apologise for the performance ahead of Friday's clash with Las Palmas:
"It's been a difficult week for everyone. For us and for you. For all of us who love Real Valladolid. I wanted to apologise again because last Sunday in Bilbao we were not up to the standard that this crest represents. I know well what this club represents, this history, this province, this fan base... and I know that we are indebted to you.
"We have worked hard to compete at 100% tomorrow and go for the victory. That is why I want to ask you to come to Zorrilla tomorrow and give us the opportunity to show that we are all together: you and us. I ask you to encourage my teammates and push them as you have always done. We need you! All for the purple!"