Jean-Eric Vergne believes the Ferrari pairing of Fernando Alonso and Kimi Raikkonen could be a "time bomb" waiting to explode.
Next year Raikkonen would return to Maranello to the team with whom he won the 2007 Drivers' Championship title.
The Finn's second stint at Ferrari will see him partner Alonso in what many feel is the strongest line-up on the 2014 grid.
However, Vergne reckons it also brings with it a host of problems.
"Alonso is without a doubt one of the candidates to win the title in 2014," the Toro Rosso driver told Corrierre dello Sport.
"What worries me is the arrival of Raikkonen in place of Massa. Kimi is a great driver like Fernando but together they could be a time bomb for Ferrari."
But no matter how the Ferrari pairing plays out, Vergne expects Red Bull will again have the edge over the Scuderia and the rest of their rivals.
"Even with the new rules I do not think that the balance of power can change so quickly. I think that Red Bull area ahead of the Ferrari and it will be so again next year."
He also weighed in on the decision to award double points in the 2014 season finale in Abu Dhabi saying it is "unfair.
"It undermines what has been done by a driver during the season. It is a rule that is imposed on us but we drivers are not happy with this."