AUSTIN, Texas (AP) — Ferrari team boss Maurizio Arrivabene watched his red cars slip and splash around a wet Circuit of the Americas while Mercedes' Lewis Hamilton cut the quickest laps of the U.S. Grand Prix practice session.

A few minutes later, Arrivabene sized up the task in front of Ferrari and driver Sebastian Vettel: Win Sunday or stay close enough to Hamilton to keep alive their rapidly-vanishing hopes of winning the season championship.

"We are here to compete with a mission impossible," Arrivabene said Friday. "I know the numbers are all against us ... our job is to go there to the track without giving up."

That's an apt summation of Ferrari's fading title chances on a Texas racetrack about an hour north of the Alamo.

With a 67-point lead and just four races left, Hamilton can win the championship Sunday with any result that puts him eight points clear of Vettel. If Hamilton wins, which he's done here five of the previous six years, Vettel must finish no worse than second to extend the championship into next week in Mexico City.

Even that got harder to do Friday when the early practice session produced another Ferrari unforced error in a season full of them. Vettel was given a three-place starting grid penalty for not slowing down quickly enough under a red flag. He was second in Saturday's qualifying, and will start fifth.

"We mustn't look at the past as we can't change it," Vettel said when Ferrari arrived in Texas. "We need to focus and look forward to the next four races. We will still try to do our best and then we'll see what happens."

No one at Ferrari wants to look at the past eight months. They would only see another collapse for the most famous team in racing.

Ferrari hasn't won an F1 driver's championship since 2007. This season looked like it could be the one to break the drought.

Vettel sparked a potentially delicious duel with Hamilton by winning the first two races. For a few months it was, as the two four-time champions chased a fifth title to tie Argentina's Juan Manuel Fangio. Only Germany's Michael Schumacher has more (seven).

And early on, even Hamilton had to admit Ferrari had the better car.

But Ferrari's problems began mounting in the form of self-inflicted errors by drivers, crew and management, while Hamilton was sharpening into his typical second-half dominance.

A Ferrari team mechanic's leg was broken when Kimi Raikkonen's car was released too early from a pit stop in Bahrain (a race Vettel won). Vettel crashed out from the lead late in the rainy German Grand Prix, allowing Hamilton to win.

A week later in Hungary, Vettel spun out in qualifying. In Japan, a team gamble resulted in a poor tire choice in qualifying that cost Vettel dearly again.

And tragedy struck Ferrari when Chairman and Chief Executive Officer Sergio Marchionne died in July from complications after surgery.

Vettel's last win came in Belgium on Aug. 26, and he hasn't finished better than third since. He didn't even make the podium in Ferrari's home race in Italy.

Hamilton won Italy and Vettel fumed about an opening-lap collision between the rivals. Most saw it as a good move by Hamilton in wheel-to-wheel racing.

Vettel has been the target of pointed criticism over his mistakes. Hamilton, who has been steadily choking off the championship with six wins in the last seven races, defended Vettel on social media this week. Hamilton demanded "more respect for Sebastian" from media and fans.

"As a four-time world champion, it is the most intense year that we've had," Hamilton said in Texas. "Every hiccup is magnified ... But there have been many, or several, times that I've been in the firing range and Seb's always been really respectful and supported me, so I thought it only just to do the same."

Arrivabene also defended Vettel.

"Criticism of Sebastian is not coming from the team. I have said many, many times, we are winning and losing together," Arrivabene said.

Changes are coming in 2019, some for certain, others rumored.

Raikkonen, the last Ferrari driver to win a championship, is leaving. He'll be replaced by Sauber's Charles Leclerc. Ironically, Leclerc is the driver whose spin on the track Friday prompted the red flag that led to Vettel's critical penalty.

Leclerc has shown considerable skill and scored impressive results this season in an overmatched car, leading to speculation he could challenge Vettel once he's in a Ferrari.

Italian media have linked Arrivabene with a possible move to management in the Juventus soccer club. Arrivabene was appointed team principal at Ferrari by Marchionne in late 2014 with hopes he could deliver an elusive championship.

"I said my future is in Ferrari, but it (is) the top management that have to give me their final blessing," Arrivabene said.

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