ANY hopes for a harmonious end to Daniel Ricciardo’s time at Red Bull are fading after team boss Christian Horner lobbed a couple of grenades at the Aussie in a recent interview.

Still reeling from Ricciardo’s surprise decision to leave for Renault at season’s end, Horner spoke at length about what he believes are the reasons behind the move — and he didn’t miss.

In an hour-long episode of F1’s official podcast Beyond The Grid, Horner indicated Ricciardo was running from a battle with teammate Max Verstappen he knew he couldn’t win.

“It’s a great shame he’s chosen to leave the team, but I guess in his mind he’s felt that after five years he needs a new challenge,” Horner said.

“He’s chosen to join the Renault team he feels are in the ascendancy. He knows the Renault product very well from all the time he’s spent with us. And I can’t help but feel he wants to be a leading role perhaps in a smaller environment.

“The competition between he and Max is intense. Max is growing stronger and stronger and I think Daniel has decided the timing is right for him to check out and try something else …

“He said he wanted a change. You look at the rational reasons for that, it’s hard to understand.

“I think it comes back to wanting to take on, in his words, a new challenge. But he sees Max growing and growing in terms of speed and strength and he doesn’t want to play a support role … not that they’re in any way treated any different.”

Ricciardo (118 points) is currently ranked ahead of Verstappen (105) in the drivers championship but has regularly been slower during qualifying.

Horner insisted the 29-year-old “would have had absolute equal status, as they’ve always had” and the team had done everything in its power to convince him to stay.

“I have to admit it’s kind of been like trying to convince a girl to go out with you that’s been pretty reticent. It’s felt like that,” he said. “Daniel’s had conversations with (Red Bull owner) Dietrich (Mateschitz), with myself, with (team adviser) Helmut (Marko) and we’ve bent over backwards to make it happen. But if someone’s heart’s not really in it … it’s felt like that. In the end we gave Daniel everything he wanted and asked for and it still wasn’t enough.

“It wasn’t about money, it wasn’t about status, it wasn’t about position or commitment or duration. He felt I need to take something else on at this stage of my career. It might be an inspired choice, it might be one he regrets.”

“I could understand if it was to Mercedes or Ferrari,” he added. “But it’s an enormous risk at this stage in his career.

“We were even prepared to do a one-year agreement so he was available to Ferrari and Mercedes should they come knocking in 12 months time.”

In a wide-ranging conversation, Horner took another jab at Ricciardo when discussing the rivalry between fellow Aussie Mark Webber and Sebastian Vettel at Red Bull.

“It was potentially where Ricciardo-Verstappen could have ended up over the next couple of years,” he said. “It was very difficult for Mark to accept at the time — and if he looked back at it now with perspective and honesty — Sebastian was just quicker.”

Horner said the team’s preferred route was to replace Ricciardo with a driver from the Red Bull stable. He ruled out dual world champion Fernando Alonso.

“I’ve got huge respect for Fernando, he’s a fantastic driver, but he’s tended to cause a bit of chaos wherever he’s gone,” he said. “I’m not sure it would be the healthiest thing for the team … our preference would be to continue to invest in youth than take a driver who is closest to the end of his career.”