BARCELONA -- Juan Carlos Unzue spent the last three years in the home team's dugout at Camp Nou but will be on the visiting bench on Saturday when his Celta Vigo team travel to Barcelona.
Unzue, 50, was Luis Enrique's assistant and was considered for the top job at Barca in the summer before eventually missing out to Ernesto Valverde.
Subsequently named the Celta boss, he returns to Catalonia this weekend looking to extend the Galicians' good run of results against Barca.
In each of the last three seasons, Celta have beaten Barca -- albeit only once at Camp Nou -- and it is something which Valverde says has been prevalent in his thoughts this week.
"Of course we consider [recent] results against them," he told a news conference when asked if Celta's bête noire status was something which worried him.
"They have had good results against Barca in recent seasons -- we know all about the previous games. They don't tell us everything, but they do show that you have to be careful."
But it is the presence of Unzue, the former goalkeeper who was a teammate of Valverde's at Barca in the late 1980s, and his knowledge of the club which the former Athletic Bilbao coach cites as a particular concern.
"Unzue was at Barca for many years and knows the club inside out," he added. "Celta have a way of playing where they like to dominate the play and I am sure they will do same on Saturday, which is something we have to worry about.
"I think it's dangerous that [Unzue] knows Barca so well. I was the coach at Athletic before and when you play against Barca you need to approach things differently.
"In that sense, the internal knowledge Unzue has can be a big bonus for him and it will make it harder for us. He is a very studious coach, he picks up on lots of little things and he's a dangerous coach to play against."
Valverde has Sergi Roberto and Andre Gomes fit and available for selection again for the visit of ninth-placed Celta, which has seen Nelson Semedo and Gerard Deulofeu cut from the squad.
Deulofeu has come in for criticism in recent weeks but Valverde warned against reading too much into his squad selection.
Barca go into the game with a four-point lead over second-placed Valencia and there is an eight-point drop down to Real Madrid and Atletico in third and fourth respectively.
However, despite a 19-game unbeaten run in all competitions, headlines in the local press still focus on potential signings.
On Friday, both Sport and Mundo Deportivo reported there was belief inside the club that a deal could be done for Liverpool's Philippe Coutinho in January for around €145 million.
"We've been speaking about players for a long time that aren't part of the club when we can't sign anybody," Valverde said when asked if Coutinho's ineligibility in the Champions League could break the deal.
"Let's focus on what we have to do right now. We have the Celta game, then Sporting [Lisbon] in the Champions League... It's damaging to talk about [transfers] when the window is closed."
Likewise, he did not want to talk about outgoing players, saying he has not spoken with Arda Turan, who has not played a single competitive minute this season, about leaving the club in the winter.