Bellingham -- who is Real Madrid's top scorer this season with 13 goals in all competitions -- fell awkwardly in the first half of his team's 0-0 LaLiga draw with Rayo Vallecano on Sunday and has been a doubt for Wednesday's group stage match at the Santiago Bernabeu.
"I don't know if he'll play [against Braga]," Ancelotti said in his prematch news conference.
"He's recovered well. He was comfortable in training. He didn't take part in the whole session to protect the shoulder, but he felt fine in all his movements. I'll evaluate it tomorrow with him."
Club captain Nacho Fernandez praised Bellingham's "Real Madrid DNA."
"He's a fighter and a winner," Nacho said. "In every training session and every game, he only cares about competing and winning. He's started in the best way possible, scoring a lot of goals, and helping the team. He's shown he has what it takes. It's a huge joy to have this kind of player here."
Madrid are top of Champions League group C with maximum points after wins over Union Berlin, Napoli and Braga so far, but Sunday's goalless draw saw them fall two points behind leaders Girona at the top of LaLiga.
Ancelotti denied that the team's ability to score goals -- beyond Bellingham -- is a concern, after criticism of forwards Vinícius Júnior, who has two league goals this season, and Rodrygo Goes, who has one.
"I think if you concede fewer [goals] you have more chance of winning," Ancelotti said. "In our time here we score two goals a game on average, and I think right now we're there more or less. That's what's important. The team has done a lot defensively this season, with a lot of clean sheets and that means you don't need so many goals."
"We have to be patient [with Rodrygo]," Ancelotti said. "Forwards go through these spells, sometimes you shoot a lot and you don't score, other times you touch it and it goes in. Rodrygo is the player with most shots in LaLiga. He moves well, he gets into the box, sometimes his shot is blocked or he isn't efficient... This moment will pass."
Vinicius' attitude has also been questioned after frequent clashes with opponents, including in last month's Clásico. Former Barcelona captain Carles Puyol said this week that Vinícius would get "more recognition" if his on-field attitude changed.
"We've talked to [Vinicius] a lot, since he arrived at Real Madrid," Nacho said. "Maybe he's the type of player who is provoked more than others, with his way of playing, he takes players on, he hurts the opponent... He's changing bit by bit. It's inevitable, he has a lot of character, he'll get into some altercations. He's well looked-after here.
"If Puyol wants to talk personally to Vinicius let him do that, he has a lot of experience," Ancelotti added. "Vini keeps making the difference. That's what we think. Maybe he has to improve his attitude in some circumstances. But also he's improved a lot, and he's still improving, and we're delighted with him, with what he does on the pitch."
Real Madrid announced a new contract for Eduardo Camavinga on Tuesday, with the midfielder, 20, extending his deal at the Bernabeu until 2029.
"Real Madrid and Camavinga have agreed the extension of the player's contract, keeping him at the club until June 30, 2029," Madrid said in a statement.
"Camavinga arrived at Real Madrid in 2021 aged just 18 and in his first two seasons has won six trophies... At just 20 years old, [Camavinga] has already played 114 games wearing the Real Madrid shirt."
It follows confirmation of new deals for Vinicius and Rodrygo last week.