Chelsea received a boost this week when James returned to training after two months out with a hamstring injury.
Mount suffered an ankle ligament injury in the Club World Cup final earlier this month but the midfielder was back on the bench in the Champions League win over Lille , Tuesday.
Kovacic limped off in the 2-0 win at Stamford Bridge in midweek, while Ziyech was also sent off in that game.
Chelsea take on Liverpool at Wembley on Sunday and Tuchel provided an update on his fitness in his pre-match press conference on Friday afternoon.
Tuchel said: “We trained today with everyone on the pitch except Ben Chilwell. That’s about it.
“Kovacic and Ziyech are fine. Everyone joined the practice squad from the last to the first minute. I hope it stays that way. We have another practice tomorrow.
Pushed on whether James could start, Tuchel said: “Even if I wanted to, I’m not sure I can answer your question now.
“He looked brilliant in the last two training sessions. Let’s wait and see if I’m crazy enough to put him on the pitch. You’re tempted to do that.
“Let’s see, we have a little time.