Madrid fell to their heaviest ever Champions League defeat at the Santiago Bernabeu on Wednesday evening, after being beaten 3-0 by Viktor Goncharenko’s side.
Real had already secured qualification for the knockout stages as group winners, giving Solari an opportunity to give some Champions League game time to some of his younger, less experienced players.
But that decision backfired and Solari has admitted that his side “were not strong in any of the areas” in what was their second group stage defeat this term.
"I'm leaving sad because of the result. I know we take risks. I have it clear,” the Real Madrid boss said.
“The match could be different, because it depends on the strength. We were not strong in any of the areas.
"I did not like the second half. I must take responsibility for the team that I fielded and the game I am proposing, with many young guys.
“It has helped us to give them experience and they need it: young players, players who need rest and those who come back from injury. It is not a path of roses.
“We do not like the result. We had confidence in a victory.”
One player who has struggled for game time since Solari took over from former coach Julen Lopetegui is midfielder Isco.
The Spain star was one of a number of players to struggle against CSKA, with the home crowd voicing their disappointment at his performance level on a number of occasions.
At one point, Isco appeared to turn on the Real supporters by shouting back in their direction.
Solari insists he is not bothered about the crowd’s actions and says he did not see Isco react.
"I do not care about Isco's boos. The fans express themselves because they do not like the result in general. But we do not like it either,” he added.
"I have not seen Isco's gesture to the crowd. Marcelo returns from injury, and we will work together to find his best version.”