Lotus boss Eric Boullier says Romain Grosjean must seize the opportunity of Kimi Raikkonen's departure and prove he can lead the team in 2014.
Grosjean has been comprehensively outscored by Raikkonen over the past two seasons, and this year is almost 100 points adrift of the Finn.
He has been more of a match over the last five grands prix however, outqualifying Raikkonen on three occasions and outscoring him twice.
While Lotus has admitted it fought to keep star driver Raikkonen for next year, it says Grosjean must now step up and prove he can thrive once out of Raikkonen's shadow.
Asked by AUTOSPORT if Raikkonen's departure made Grosjean's role safer, Boullier said: "Not more secure I would say, but it gives him the opportunity to stand up.
"When you are a young driver and you are racing against Kimi and obviously the personality and charisma and results - it is good to grow up.
"But to stand up is more difficult, so now Kimi is leaving it is the right opportunity for Romain to show us what he can do.
"It is up to him. He did a good job in the last four races, nobody complains and I am happy, so he now needs to do the same, plus..."
Grosjean, who narrowly missed out on the front row at Singapore, said last month that his 2013 form had helped him shed the image of being Formula 1's "black sheep".