Ahead of Saturday’s LaLiga clash at home to local rivals Girona, Flick labelled the talk rubbish, asserting his autonomy over team selection and his positive relationship with Deco.
"I don’t know where you have got that information from, but at the end, I’m sorry about the choice of words, but it’s totally bullsh*t, okay?!" Flick told a press conference.
"I never, never, was asked that. I really appreciate how they believe in my work. They would never ask me something like this. So I can say it’s bullsh*t! And if someone said this he’s lying."
Barca, who trail LaLiga leaders Real Madrid by two points, face Girona amid a mounting injury crisis that leaves Flick without eight first-team players, including striker Robert Lewandowski, who suffered a torn thigh muscle with Poland.
The Catalans are also missing Dani Olmo, Gavi, Yamal, Fermin Lopez, Raphinha, Joan Garcia and Marc-Andre ter Stegen.
"I cannot change it. We have to find solutions," Flick said of the injury woes, which have sidelined more than 30% of Barcelona’s senior squad.
"Lamine Yamal and Fermin Lopez came back (to training), but they cannot play the full 90 minutes. We might have to rely on players from La Masia (Academy). We will see what happens."
Despite the setbacks, Flick remained optimistic, particularly regarding the return of Raphinha ahead of next week’s El Clasico against Real Madrid.
"Our plan for El Clasico is that (Raphinha) will be back. There were some problems with his recovery, but he’s on a good way," he added.
Flick also defended 37-year-old Lewandowski, praising the forward’s commitment to his physical condition.
"No one takes care of his body more than Robert. Maybe (Cristiano) Ronaldo, but no one else at this age is on this level. He didn’t even think he was injured while playing with Poland. It’s not good for us, but we have to work with that."
Barca enter Saturday's match under pressure having suffered consecutive defeats by PSG at home in the Champions League and a humbling 4-1 loss at Sevilla in LaLiga before the international break. Flick urged his players to show greater commitment and to fight for every ball.
"It’s about attitude and mentality on the pitch," he said. "We are Barca. Our fans want to see us fighting for every situation. Last season we won three titles, but this is a new season. We have to start now with the same attitude, and I think we will fight tomorrow."