The striker has been eased back into action by Thomas Tuchel and is yet to start a match since his return from injury, and he will have to settle for minutes off the bench again.
Lukaku has made two substitute appearances since being ruled out for a month with ankle trouble.
Chelsea boss Tuchel, who has been managing the £97.5million striker’s minutes since his recovery, said: “He is in training, he wants to start.
“How difficult is it to reach the top level? It is also difficult for Romelu and the other guys who have come in after injuries to hit their top level.”
Chalobah will have further tests to determine the severity of his injury, meaning Andreas Christensen continues at centre-back against West Ham.
Jorginho partners Ruben Loftus-Cheek in midfield, while Timo Werner is also fit again and makes the bench.
Chelsea XI:Mendy, Christensen, Silva, Rudiger, James, Loftus-Cheek, Jorginho, Alonso, Mount, Havertz, Ziyech
Subs: Kepa, Azpilicueta, Sarr, Saul, Barkley, Hudson-Odoi, Werner, Pulisic, Lukaku