Christensen was reportedly in line to start against Liverpool at Wembley Stadium before he spoke with Tuchel on the morning of the game, telling the Blues boss that he felt he could not play.
The Denmark international, who is expected to sign for Barcelona on a free transfer in the summer, has been in and out of the squad since the March international break.
For that reason, Tuchel has indicated that that he half-expected that an issue may arise, as well as acknowledging that the centre-back may have played his final game for the club.
Speaking to reporters at a press conference, Tuchel said: "Not sure yet if he's involved tomorrow and at the weekend.
"Andreas came on the morning of the match and told me he was not ready to play the match. He had his reasons, they stay private and confidential, but it was not the first time as you can see over the last weeks we had some of the same situations why he did not play so regularly.
"We thought that we are in a good progression and good development because he played very strong in the match before the final against Leeds but the conversation took place and we have to respect it and we of course respected it and he has our support.
"It is unlikely for the weekend, it was on very short notice before the cup final and other matches in the weeks before. So no chance I have any prediction for tomorrow and the weekend."
While the 26-year-old has made a total of 33 appearances in all competitions this season, he has featured just once in the last six games. body check tags ::