Lewis Hamilton's father, Anthony, has warned new Mercedes recruit Valtteri Bottas that his move could prove "career-ending" if he doesn't live up to expectations.
The Finnish driver joins Mercedes from Williams on a one-year deal after Nico Rosberg opted to retire at the end of the 2016 season, having achieved his goal of becoming a world champion.
Hamilton Snr says going up against his son, who he believes has yet to reach his peak despite having won three titles, is something a driver must consider carefully before agreeing to partner him.
"Anybody who goes up against Lewis needs to have planned their career correctly because it could be a career-ending move when you go up against Lewis," he told Sky Sports.
"I personally think, while he's getting older and more mature, he's still actually heading towards the prime of his career. So Lewis is going to be a force to be reckoned with this year."
Hamilton's defeat to Rosberg is only the second time in his career a team-mate has beaten him – having been outscored by Jenson Button at McLaren in 2011 – and Hamilton Snr says his son is now looking forward to reclaiming the crown.
"Lewis only ever thinks about winning," he added. "He's happy for Nico, like we all are to be quite honest. We've known him a long time and Nico has really worked hard.
"You need a little bit luck along the way, and he's had that, but I think Lewis is just looking forward now to winning the championship back on his own merit."