New signing Raheem Sterling has never worn the No 9 shirt in his career and will wear 17 at Chelsea, while Kai Havertz has stuck with his favoured 29, Timo Werner is No 11 and Armando Broja has taken the No 18 shirt he wore on loan at Southampton.
Tuchel added: “I’m also superstitious, I can understand why players maybe don’t touch it and have other preferences. It’s like this, but I think Raheem will help us a lot and in general it’s our responsibility to create more offensive positions to have maybe a bit more players in the box.”
Chelsea completed the signing of left-sided defender Marc Cucurella for £55 million, plus £7m in add-ons, and, despite Leicester City’s insistence he is not for sale, have not given up on centre-back Wesley Fofana, who they have made more than one bid for and believe wants to move to Stamford Bridge.
Talks have been held over midfielder Frenkie de Jong, who Chelsea believe would join them over Manchester United if he decides to leave Barcelona.
Cesar Azpilicueta has signed a new two-year contract, but Tuchel confirmed that he would still like to sign another defender, even though Chelsea may have to pay more than the £80m world record fee for a defender to land Fofana.
Tuchel said: “Azpi and Trevoh Chalobah play in the same position in the back three, Marc can play in the back three on the left. Kalidou (Koulibaly) can play in the back three on the left and we have Thiago Silva who is not getting younger, unfortunately. So maybe we bring in one player, maybe not. Let’s see if we can make another signing.”
Teenage defender Levi Colwill has joined Brighton on loan and Chelsea have held talks over finding an agreement for Werner to return to RB Leipzig and Kepa Arrizabalaga to join Napoli on loan.
Cucurella, who has signed a six-year contract at Chelsea, said: ‘I’m really happy. It’s a big opportunity for me to join one of the best clubs in the world and I’m going to work hard to be happy here and help the team.”
Co-controlling owner Todd Boehly, who is interim sporting director, added: “Marc is an elite defender of proven Premier League quality and he further strengthens our squad going into the new season. We continue to work on and off the pitch, and we’re delighted Marc will be a part of the present and future at Chelsea.”