While Ferrari has signed Charles Leclerc to a long-term deal, locking in the Monégasque star until the end of 2024, Vettel is out of contract at the end of this season.
Last year, the German was dogged by rumours that 2019 could be his final season in F1. This year promises more of the same.
Ferrari team boss Mattia Binotto said earlier this year that he would begin talks with Vettel come May, after the first few races had been run.
Those, however, are on hold with the championship only expected to begin in mid-June - if even then.
In the meantime, rumours about Vettel's future continue with reports linking him to McLaren and Carlos Sainz to his Ferrari race seat.
Leclerc doubts all of that will throw Vettel off his game when the season eventually begins.
He told Motorsportweek.com: "I feel very lucky to be in a position where I have a long-term contract and I am happy to be in this position. I also know in his position, in a way, as my last two years I only had one-year contracts. I don't think it will destabilise him.
"He is a very strong driver and I expect him to be strong anyway."
Battles stay on track
The two-time grand prix winner also touched on his relationship with Vettel, which was at times strained last season.
At times both were unhappy with Ferrari's use of team orders with the rivalry resulting in a double DNF as they collided at the Brazilian GP.
Leclerc maintains that while it was "tricky" out on track, it never spilled over.
He said: "With Sebastian the relationship has always been good. Last year there have been some tricky moments but our relationship stayed the same, which I think is a good thing. I think we are both mature enough to do the separation on what happens on track and off track."
Leclerc is happy to continue with Vettel as his team-mate come 2021.
He added: "I am very good with him by my side but I will respect Ferrari's decision in case they want to change."