Thiago has stepped up his recovery from a thigh injury he suffered against Tottenham earlier this month.
But Sunday’s game against United comes too soon for him, Thomas Tuchel has confirmed.
The Chelsea manager said: “Thiago cannot play on Sunday.
“He did an individual session today, on the pitch, and it was a big progress and step ahead up front for him so I hope he will join the group next week.”
Chelsea face a pivotal run of games in their bid to secure Champions League qualification.
After United, they face a trip to Anfield and then take on another top-four rival in Everton.
Olivier Giroud leads the line here after a Champions League winner at Atletico, while Mason Mount and Hakim Ziyech offer attacking support.
Ben Chilwell and Callum Hudson-Odoi start on the flanks with N’Golo Kante affer a rare start in midfield alongside Mateo Kovacic. A three-man defence of Cesar Azpilicueta, Andreas Christensen and Antonio Rudiger sit in from of Edouard Mendy.
Chelsea XI: Mendy, Azpilicueta, Christensen, Rudiger, Hudson-Odoi, Kante, Kovacic, Chilwell, Ziyech, Mount, Giroud
Subs: Arrizabalaga, Alonso, Jorginho, Pulisic, Werner, Zouma, James, Havertz, Emerson Palmieri
Injury list: Thiago Silva
Chelsea squad from: Mendy, Azpilicueta, Christensen, Rudiger, Hudson-Odoi, Jorginho, Kovacic, Alonso, Mount, Werner, Giroud, Arrizabalaga, James, Zouma, Chilwell, Kante, Havertz, Ziyech, Pulisic, Abraham, Caballero, Emerson, Gilmour