Eto'o had been struggling with a hip injury sustained during the UEFA Champions League clash with Basel last week and missed his side's 3-1 victory over Southampton.
The striker has made a quicker than expected return to fitness and could be involved at the Stadium of Light, yet the news is not as good regarding two of Chelsea's Brazil internationals.
"Eto'o is back training with the team," revealed Mourinho. "I will have to see today but he looks fine. There is a chance he can play tomorrow.
"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. Let's see for the weekend (game against Stoke at the Britannia Stadium).
"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 having not 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 added.
"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."
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