The Spain international suffered a knee injury against Manchester United in Chelsea's 3-1 win earlier this year.
But he's recovered from the ligament problem sufficiently to feature in the Chelsea squad as they look to take three points from the Hawthorns this week.
Chelsea boss Jose Mourinho confirmed that John Terry will miss the game but revealed the good news regarding Torres.
"Fernando is back and available for selection," Mourinho said.
Samuel Eto'o has led the line in his absence, although the Cameroonian has continued to labour in front of goal.
Branislav Ivanovic scored the winner against Manchester City while Eden Hazard hit a hat-trick against Newcastle last weekend.
As for the club's transfer business, Mourinho admitted that he's extremely satisfied with January's activity.
The Blues offloaded Kevin de Bruyne and Juan Mata while they brought in Nemanja Matic from Benfica and Mohamed Salah from Basel.
"In this transfer window Chelsea have made roughly a £23m profit," Mourinho added. "There are no arguments against that."