Sauber driver Charles Leclerc admits the memory of Jules Bianchi's ultimately fatal crash in 2014 makes his first trip to Suzuka "very difficult".

The close friendship between the two families is well-known with the Monegasque recently crediting Bianchi for his rise through the motorsport ranks which will culminate in a Ferrari seat for 2019.

This weekend, however, marks four years since the former Marussia driver suffered severe head injuries after hitting a recovery vehicle in terrible conditions and for Leclerc the pain remains very fresh.

“It’s obviously a very difficult weekend,” he said in Thursday' press conference. “Jules has helped me massively throughout [my career], and more than only on the racing side, it was a bit like a part of the family, all his family, so it is very difficult.

“I’ve never come to Japan before and to do the track walk this morning was quite emotional. On the other hand I need to focus on this weekend to do the best job possible anyway, even if it’s a difficult weekend.”

First time for me in Japan. Impossible to not think of what happened here 4 years ago. We miss you Julio, I'll push to make a good week-end for you ❤️ @julesbianchi17 pic.twitter.com/xYQ3CAZZCL

— Charles Leclerc (@Charles_Leclerc) October 3, 2018

With rain forecast for much of the weekend, that likely won't settle the 20-year-old's emotions any faster but after a strong finish in Sochi, where he led the midfield in seventh, Leclerc is unsure if that form will carry over to Japan.

“I think we went with two very difficult weekends with Spa and Monza, especially for the low downforce package that for me was not so strong, then we recovered a bit in Singapore," he explained.

“Then Sochi was a track that was quite good for our car with the straight line and things like this, but we still need to keep our feet on the ground and keep working because I’m not sure we will be as competitive as we were in Sochi here, so we’ll have to see, but it might be a bit more difficult."