Andreas Christensen and Alejandro Balde both head into the final year of their contracts in 2027, with latter considering a move to the Premier League, alongside constant doubts over Christensen's future.
Flick has benefitted from having an experienced player alongside Pau Cubarsi at the heart of his defence - as shown with Inigo Martinez and Ronald Araujo in previous years - and that will form part of his defensive planning.
However, one player who will not be heading to Catalonia is Flick's former star with the German national team, Jonathan Tah.
As per an update from Sky Sports Germany, Barca have reached out to Bayern Munich over a possible deal, but that was instantly rejected by the Bundesliga champions due to Tah's importance in Vincent Kompany's squad.
The 30-year-old joined Bayern in 2025, and has become a key players, with 67 appearances - and his contract is in place until 2029.
Barca will now look at other options, particularly with Liverpool keen to make Araujo's loan into a permanent switch in 2027.