Any driver would struggle to be Max Verstappen's teammate at Red Bull-Honda.

That is the view of former McLaren team boss Eric Boullier, who was asked by Ouest France newspaper about Pierre Gasly's up-and-down 2019 season.

Fellow Frenchman Gasly moved up to Red Bull Racing for 2019 to replace Daniel Ricciardo, but by mid-season he had been relegated to Toro Rosso.

When asked if the 'costume was too big' for Gasly at the senior team, Boullier insisted: "I don't think the costume was too big for him at Interlagos!

"Red Bull is a special structure," Boullier added.

"Their strategy is conceived around performance at any price and one driver.

"So once everything is in place - a high-performing team, a factory engine and a lead driver like Max Verstappen - then there is no room for anyone else," he said.

Boullier says Gasly, 23, then simply struggled to fit in at Red Bull.

"It's very difficult for any driver, let alone a young driver, to arrive at a place as difficult as that," he said.

"Everything will be focused around Verstappen. What is exceptional is that they demoted Pierre to Toro Rosso and we now see him performing even better than he was last year.

"He has become the leader at Toro Rosso now, similar to what Verstappen is at Red Bull," Boullier added.