Leclerc has been promoted to Ferrari after one season with Sauber but his team principal Mattia Binotto has made it clear that Vettel will be prioritised early in the season if the situation requires it.
During pre-season testing Binotto moved to clarify that Leclerc is free to race Vettel but Ferrari would act if there was an "ambiguous" situation as it is counting on Vettel to lead its title push.
Leclerc said he will only know what the "50/50" situations he has referred to in the moment, and Vettel said it was "pointless" to hypothesise.
He also said during testing that Vettel knowing the team so well was an advantage, but said a a team-building weekend had helped him learn more about his new team members and believes he has grown up as a driver since his rookie season.
"I did many weeks in Ferrari['s Maranello factory] to try and get to know as much as possible the team, and also did a small team-building weekend just before coming here, which has been very helpful to know new faces," said Leclerc.