The Formula E driver did not shy away from telling reporters what he thought of Toro Rosso's newest driver.
Jean-Eric Vergne, speaking at a press conference before the Paris e-Prix, said he finds the appointment of Brendan Hartley as a Toro Rosso driver "amusing".
Vergne, who used to be a part of the Red Bull young driver programme, currently races in Formula E for the Techeetah team. He also commented on Sebastian Buemi, another former Toro Rosso driver who missed out on the Red Bull seat, and his chances of staying in Formula One being limited due to the lack of performance from the car.
"It makes me laugh that Red Bull called on Hartley, given that he's the one they fired to give me his seat in World Series by Renault," said Vergne.
"I find this rather amusing."
"(He would) probably get fired after one year, with no options in top teams, as the car is not good enough".
Vergne currently sits at the top of the Formula E 2017/18 championship standings with two wins this season.
"Joining Formula E was the most difficult time of my career when leaving F1," Vergne said. "But with hindsight, I think it was the turning point of my career.
"In any difficult or negative situation, there are positives to draw. You just need to extract them.
"I think I was lucky to join Formula E at the right time and quickly change my mentality and my state of mind. Today, I think it's the best thing that can happen to me."