Why is Pierre-Emerick Aubameyang wearing a mask for Chelsea in Champions League?

New Chelsea striker Pierre-Emerick Aubameyang continues to wear a mask to train and play since his deadline day transfer from Barcelona.

Manager Thomas Tuchel has called on the Gabonese striker to boost the Blues’ attack and kick-start their season after a stuttering start.

The 33-year-old watched his new side beat West Ham on Saturday and has since travelled to Zagreb with the squad for the Champions League group stage opener, alongside new signing Denis Zakaria, and makes his debut against Dinamo Zagreb.

When Aubameyang line up for the Blues, he will be forced to wear a mask as he recovers from a broken jaw.

The injury occurred when Aubameyang’s home was robbed last Monday while still in Barcelona.

After the incident, Aubameyang took to Twitter to explain the situation: "On Sunday night, some violent cowards broke into our home and threatened my family and my children, just to steal some stuff. They injured my jaw but I will recover in no time, and thank God no one else was physically harmed.”

Tuchel was confident a protective face mask will enable Aubameyang to contribute immediately, revealing last week: “Auba will train on Sunday but I cannot tell you yet if it’s full contact or individually. We’ll need to see. He has the mask and the doctors tell me the mask is good and he feels comfortable with it.

“So he would be okay but we need to check it and we need to check it with no contact, half-contact, and then full contact. We need to see how he feels with it. It’s too early to make a prediction but he’ll be in training.”

Tuchel added that his involvement may depend on how Aubameyang “adapts” but that “at the very latest after the national break, but we try to push things and Auba is happy to push things.”

Aubameyang reportedly travelled to Milan to obtain a personalised face mask to protect his jaw, with the orthopaedic specialist company called Ortholabsport providing the service.

The same company has helped former Chelsea players Antonio Rudiger, Fernando Torres, Demba Ba and Cesc Fabregas continue playing despite facial injuries.

Should Tuchel not believe Aubameyang is match fit or adjusted to his new teammates, then a debut could come this Saturday against Fulham.