The England international has been out of action since suffering the injury in Chelsea's 1-1 Premier League draw with Brighton at Stamford Bridge on December 29.
Chelsea will jet out to Abu Dhabi after Saturday's FA Cup fourth-round clash with Plymouth, with their Club World Cup semi-final taking place on February 9.
"Reece is not in team training yet, so he's not available this weekend," said Tuchel. "And he will not travel with us to Abu Dhabi because he's not back in team training."
The Chelsea boss said he was too experienced to get "over-excited" by putting a date on when a player would return.
"The diagnosis was straight away that it's a big injury, and from there we need to be patient," said Tuchel. "It's a hamstring, it's always tricky and he's a very physical player.
"And unfortunately he then caught the flu and that was a setback in the last few days of his process in coming back to the team."
Ruben Loftus-Cheek will also miss Saturday's match due to a knock, while Christian Pulisic and Thiago Silva are unavailable after international duty.
Chelsea were unable to bring in wing-back cover in the January transfer window after Ben Chilwell's season-ending knee injury and James' continued hamstring trouble.
Versatile Brazilian Kenedy has been recalled from a loan spell at Flamengo after Chelsea were unable to bring Emerson Palmieri back from loan at Lyon.
Tuchel said he harbours no frustrations over the lack of success in the transfer window, remaining confident that Chelsea can cope with their current resources.
Asked about the issue, Tuchel said: "No, no frustration, because I was also calm and there was no frustration because I know what kind of quality we would need to add to a very strong and a good group.
"It's also my job to find solutions when we have injuries. We tried and had ideas, but in the end we stick to what we have and we are happy with it."