The 19-goal Brazil international missed his side’s 1-0 defeat by Manchester United on Saturday due to a thigh injury.
They hope he will be available to make what would be his first return to the Amex and were leaving the decision as late as they could.
Chelsea need a boost after four successive defeats and they will be keen to increase an advantage over the Seagulls which has been trimmed to a single point.
Head coach Liam Rosenior told his Monday afternoon press conference: “Joao will be a late call.
“He was out on the pitch today. We will make a final decision on him tomorrow morning.
“So that’s positive, that it’ll be sooner rather than later.
“Estevao is definitely out tomorrow. We’ll do a further investigation into his injury.”
The Brazilian winger was hurt against United and Chelsea would love to have his invention among their options.
Rosenior is coming under pressure after what initially seemed to be a positive start as he was moved across the BlueCo family from Strasbourg.
But he says he has support from the top figures at Stamford Bridge.
Rosenior said: “They have been supportive of me in our daily conversations, they have been magnificent in their support of me and the team.
“We’re aligned that we know we need to win games of football in the now, but that doesn’t go against what we’re trying to do, which is give consistent success to this club long-term.”
With just three points separating the Blues and Fulham in 12th, Rosenior’s side are in danger of missing out on European football altogether.
“We’ve made it very difficult for ourselves,” he said of their Champions League aspirations. “We have to be honest and realistic with that.
“But what we can’t do is give up. We have to keep fighting. We have to make sure we go to Brighton with similar attributes to what I saw against Manchester United in terms of our energy, our intensity and engagement to the game, which was good.
“But we didn’t keep a clean sheet and we didn’t take advantage of the chances, so we need to be more clinical and more ruthless in both boxes.”
Rosenior revealed defender Wesley Fofana has apologised for his reaction to being substituted against United.
The 25-year-old centre-back, who will be considered for selection at the Amex, ignored Chelsea’s coaching staff as he left the pitch.
Rosenior, the former Albion full-back, said: “Wes is a very emotional character, in a good way. I love him.
“He’s not afraid to wear his heart on his sleeve. I’ve spoken to him about it, and he’s just disappointed that we’re losing a game.
“I think he could have shown that emotion in a better way. That’s something I’ve spoken about.
“The optics on that is not the reality. The reality is I’ve got a really good group, who are working really, really hard for me and the staff and for the club.
“At the moment, the results aren’t going that way and then people start reading more into it than what it actually is.”
Chelsea have lost six of their last seven games in all competitions, the one win coming against Port Vale in the FA Cup.