Andoni Iraola is against the clock in the transfer window with Barcola a long-term target for the Spanish coach after weeks of talks with the UEFA Champions League holders.
The main blockage has been Liverpool's refusal to match PSG's rumoured £130-45M valuation of the France international with Mbaye's exit fee set at £35M.
Liverpool want to take around 20% off both deals before agreeing, and that stance has been backed up by walking away from negotiations with Brighton & Hove Albion, after seeing two bids for Yankuba Minteh rejected.
As per the latest from French outlet RMC Sport, both players have been left out of PSG's Ligue 1 matchday squad to face Rennes today, as Luis Enrique continues his policy from the French Super Cup loss to Lens last weekend.
Liverpool will hope to force through an agreement, but they need a change from PSG, who have already spent over €150M on Ferran Torres, Magnes Akliouche and Mika Godts this summer.