The Cameroonian sat out Sunday's 3-1 victory against Southampton with a hip injury but may be fit to play at the Stadium of Light, according to Blues boss Jose Mourinho.
The striker had been struggling with a hip injury sustained during the Blues' Champions League loss to Basel and missed Sunday's 3-1 victory over Southampton.
The 32-year-old has made a quicker-than-expected return to fitness, however, and could be involved at the Stadium of Light.
"Eto'o is back training with the team," Blues boss Jose Mourinho confirmed to the press Tuesday. "I will have to see today but he looks fine. There is a chance he can play tomorrow [Wednesday]."
The news is not as good for a pair of the club's Brazilian internationals.
"Oscar is not in condition to play but his injury is not a serious one. David Luiz is not training with the team; he is still with the medical department," Mourinho said. "Let's see for the weekend [against Stoke City]. I hope sooner or later I have David so I can rotate a little at the back like I can in other positions."
The Chelsea boss also hinted that Ashley Cole could be set for a return to the first team, with the England international not having played since losing his place to Cesar Azpilicueta in early November.
"I think Ashley Cole will start one of these two matches, against Sunderland or Stoke," Mourinho said. "When any player that, all his career, normally starts every game doesn't, naturally they are not the happiest guy in the camp but Ashley is always professional, always a team player, so he deserves to play."