Chelsea striker Romelu Lukaku has been ruled out of his side's clash with Southampton through injury, as captain Cesar Azpilicueta is also absent having tested positive for Covid-19.
The Blues take on Southampton at St Mary's on Saturday afternoon, with Tuchel looking to bounce back from back-to-back defeats against Brentford and Real Madrid, respectively.
Lukaku, 28, has picked up a suspected achilles injury and is now expected to miss the return leg of Chelsea's Champions League quarter-final second leg in the Spanish capital against Los Blancos.
The Belgium international has endured a difficult time at Stamford Bridge since returning to the club from Juventus last summer for a club record £97.