Rafael Benitez concedes his return to Valencia as coach of Real Madrid is likely to be an emotional occasion.
Benitez memorably led Valencia to Liga titles in 2001-02 and 2003-04, along with UEFA Cup final glory in 2004.
The former Liverpool and Napoli boss is in the midst of a fractured relationship with the Real Madrid faithful but is set to be greeted by a warm reception when he takes his place in the visiting dugout at the Mestalla on Sunday.
"It will be emotional for me. I am very grateful to Valencia," Benitez told a pre-match press conference, where he warned his players that a repeat of the lack of concentration display during Wednesday's 3-1 win over Real Sociedad would be punished against Gary Neville's side.
"Valencia are a very difficult opponent. Last season Madrid suffered there [Real suffered a 2-1 defeat].
"They are a team that has enthusiasm, young players and they will be motivated very much against Real Madrid.
"If we play with intensity it will help us a lot in trying to get the win."
Benitez added: "You can ask for intensity in defence or in attack. Retrieving the ball quickly, aggressively, that's intensity - attacking quickly, that's intensity.
"It is not a matter of legs [tiredness], it is a matter of mentality, of the characteristics of the team.
"When we have struggled, we have lacked mentality. The players are aware that sometimes we do not control the game but we will give 100 per cent."