The four players are Timo Werner, Romelu Lukaku, Mateo Kovacic and Mason Mount.
Tuchel disclosed this on Monday during his pre-match press conference.
Chelsea head to the game following a 3-0 win over Newcastle United in the Premier League over the weekend.
Tuchel said, “These four players are out, unfortunately. But for Timo, Romelu and Kova no surprise.
“Mason doesn’t feel better, it’s not COVID.
“He’s just ill. Christian Pulisic is back and back in the squad for tomorrow.”
The kick-off time for Malmo vs Chelsea is 6:45 pm.