Manchester United's foreign stars believe their English teammates have been favoured in new contract talks.
Ole Gunnar Solskjaer has boosted morale since taking charge in December but some players have been surprised how difficult it has been to get their Three Amigos to commit.
United have triggered a one-year option on De Gea's contract, which now expires next season, but failed to match his market value of £350,000-a-week.
PSG have negotiated with Herrera and were willing to break through the £150,000-a-week barrier for the midfielder.
Mata is the other Spaniard in limbo and is assessing his options for next season as his United contract comes close to expiring.