Thomas Tuchel has highlighted an issue for Chelsea regarding defender Thiago Silva and his future at the club.
Silva is currently 37, turning 38 in September, and will embark on another season at Chelsea next term after penning a one-year contract extension earlier this year.
He has already been at Chelsea for two seasons, becoming a trusted and dependable player on the pitch for the Blues at the back, which has coincided with Tuchel's side becoming stronger defensively.
Chelsea could lose a large portion of their back line this summer. Antonio Rudiger and Andreas Christensen are both set to leave at the end of their current deals, while club captain Cesar Azpilicueta is undecided whether to stay or go.
They are currently unable to add players to their backline as a result of their special operating licence, however that should shortly be removed once the club's takeover is confirmed.
Tuchel is aware that work is needed to be done to rebuild the side, in particular in the defensive department, and solutions need to be found to replace and ensure there is cover for Silva who will eventually depart.
"We had a core in our back three, and we do have an issue with Thiago," Tuchel reluctantly admitted. "He is not Benjamin Button. It seems like he is, but he's not. He is getting older, and it would have maybe been enough to find a natural replacement for this kind of position and keep everybody else.
"Suddenly, we lose two, three, three-and-a-half players at the back and this is actually concerning. It is a huge, huge challenge, given the fact that you cannot act.
"Everybody else is driving from the start, and you are still not finding the right gear to get your kickstart. This is where we are. It is a long race, but we don't give up. It makes it a bit more complicated, but this is what it is. We try our very best to make up for the disadvantage, but there are some things to solve."