Valtteri Bottas did enough in 2017 to earn himself another season at Mercedes. He had a mixed first year with the team, with some career-best results and performances scattered amongst what was ultimately a disappointing campaign (by his own admission) which saw him unable to replicate teammate Lewis Hamilton's title challenge. A big improvement is necessary this year if he wants to still be driving for the Silver Arrows come 2019. Two men in particular are going to place immediate pressure on Bottas' seat.
Who is facing a make-or-break 2018 F1 season?
