Real's injury list includes Aurelien Tchouameni, Vinicius Junior, Eduardo Camavinga, while Luka Modric is a doubt after going off injured in their 3-0 win at Cadiz on Sunday.
"To talk a lot about the problems we have and the absences, I think it's disrespectful to the players who are going to play." Ancelotti told a press conference on Tuesday.
"They are contributing in a way that would never have been expected. If we've been good with all these problems, this squad, even if you didn't believe it, we have a very good squad."
One player who impressed recently is keeper Andriy Lunin. Thibaut Courtois is a long-term absentee and his replacement Kepa Arrizabalaga has missed the last three games with injury, and Ancelotti is happy to have competition in this position.
"He's (Lunin) not going to think that tomorrow is his last game. The day he returns, Kepa will compete with Lunin, this is what Lunin has earned by playing very well," the manager said.
"Competition is good. We have two high-level goalkeepers. Everyone can contribute with their own qualities."
Jude Bellingham has scored three goals in his three Champions League games this season, to add to his 11 LaLiga goals in 12 games, and Ancelotti is full of praise for the 20-year-old former Borussia Dortmund player.
"The English have sometimes had problems adapting to Spanish football. Bellingham is a mature player and a fantastic player, who adapts to any country in the world."
Ancelotti's side have already secured qualification to the knockout rounds after four wins from four Champions League games, and only need a point against Napoli on Wednesday, who they defeated 3-2 in Italy, to guarantee top spot in the group.
"Tomorrow's game allows us to finish the group stage where we have done very well so far," Ancelotti said.
"The first leg was balanced. I think it will be similar. Their counters are dangerous with (Victor) Osimhen and (Khvicha) Kvaratskhelia."
Real Madrid are on 12 points in Group C with Napoli five points behind in second. The Serie A side can join Real in the last 16 with a win in Spain or matching Braga's result with Union Berlin.
