Jenson Button believes Red Bull and Honda will have to win a winning package this year or risk losing most of their assets: Max Verstappen.
Red Bull Racing has decided to pull the long-standing Renault engine supplier into a new partnership with Honda, which will be launched in 2019.
While no one waits for a fireworks at the start of a pair, Milton Keynes equipment will have to remain a consistent front-runner, or Verstappen could look for a greener pasture elsewhere, says newcomer Sky F1 pension Jenson Button.
"It's hard with Max," said former F1 driver Sky Sports News.
"He always moves forward and always looks for something else, jumping into Red Bull and winning the first race.
"This year is a really important year for him to stay on the move.
"He has to fight for a championship, or I think he'll start wondering where he should be in the future."
Button hopes to have another thrilling three-way fight between Mercedes, Ferrari and Red Bull. The battle perhaps improved by Formula 1 rules will change in 2019, Button counts.
"There is so much change in sports at the moment, and that's exactly what sport needs," Button said.
"I think we will have three teams to fight, and if we do, it will be some fantastic games."
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