The Spain forward Pedro joined the club from Barcelona for £21m yesterday.
Goalkeeper Thibaut Courtois will return to the Blues XI for the match at The Hawthorns, having served his one-match suspension for his red card against Swansea City on the opening weekend of the season.
Victor Moses is Chelsea's only real concern. The winger confirmed this week that he has a "small injury", although he did not disclose exactly what.
Jose Mourinho's side will be aiming to get back to winning ways after their 3-0 defeat by Manchester City last weekend.
Sergio Aguero, Vincent Kompany and Fernandinho scored for City in the win at the Etihad Stadium.
After the match, Chelsea manager Jose Mourinho claimed that his Chelsea team were the "best team in the second half" and that the 3-0 scoreline in which they were defeated by Manchester City was "completely fake".
City dispatched of Chelsea with the convincing victory, but Mourinho refused to admit he lost to a better team.
"The best team in the first half won the game; the best team in the second half was Chelsea for sure," the manager said after the game.
"If the 1-0 was doubtful, the 3-0 is completely fake. Chelsea was the best team in the second half.