Mark Webber thinks a bad 2017 could force Sebastian Vettel to leave Ferrari

Mark Webber believes former team mate Sebastian Vettel could leave Ferrari if they have another difficult season in 2017.

The Italian team have so far failed to win this year and have slipped behind Red Bull to third in the standings, and Webber, who raced alongside Vettel at Red Bull between 2009-2013 has said that next year is vital.

"The momentum, consistency and getting the team together has not worked,"  Webber told The Sun. "Even things like reliability, they've not even managed to bag that," said the Australian. "Strategy looks flaky at times. They look reactive rather than proactive, so next year is a massive year for them."

"Next year is a massive year for Ferrari and Sebastian," he said. "It is a juggernaut in terms of their collective belief in the team and whether they have the weapons in place to get the job done."

F1 legend Sir Jackie Stewart agrees, saying that the departure of technical director James Allison has left the team "disoriented".

"It didn't help that it separated with its technical director halfway through the year," he told La Gazzetta dello Sport. "The team was used to him as a leader and it takes time to recover from that. James Allison had managed to unite the team and win the trust of the people -- for me, he is an outstanding engineer."

"Ferrari seems disoriented," Stewart added. "They had come to the point where they wondered why they were not winning races."