The 24-year-old was a notable omission when Tuchel named his group for the Nations League matches against Croatia and Spain, despite England making contact with Chelsea to check his condition before Friday's announcement.
According to reports, the club confirmed that Palmer was ready to be considered. His absence was therefore a selection decision rather than the result of an ongoing fitness problem.
Palmer has made a positive start to the season under Xabi Alonso, registering three goals and three assists in nine Premier League appearances as Chelsea moved into fourth place. His form had strengthened the case for an England return, particularly after he missed the previous international camp.
Palmer was selected for England in September but withdrew because of what was described as a minor injury. Tuchel had subsequently expressed frustration that the forward had missed too many opportunities to impress while away with the national team.
The England manager maintained that position when discussing his latest selection, explaining that he wanted to reward the players who had been part of the previous camp.
"I guess everyone is desperate to play for England and Cole is no exception. We are speaking now about a player that is not in camp. It counts when you are in camp and I just said last time that he misses too many opportunities to impress.
"It was a long camp, it was two and a half weeks and the players and the boys who were in camp built something extraordinary. That's why the credit goes to them, the trust is for them. If you are in camp, this is your chance to impress.
"So it's not personal and of course we will never assume that Cole is not in the mindset to come and desperate to play for his country, but the competition is on and the players who were in camp did an amazing job and kept their place."
Tuchel's decision also reflected the competition for attacking positions, with the manager opting to retain much of the group that had impressed him during the previous international window.
Borussia Dortmund midfielder Jobe Bellingham and Fulham's Josh King were among those selected, with both earning opportunities to impress at senior international level.
Palmer's omission is another setback after a difficult period with England. He was previously overlooked for the summer's World Cup squad following an injury-disrupted campaign, and his latest absence means he must continue making his case through his performances for Chelsea.
His current availability, however, removes one potential obstacle to a return. Tuchel has made clear that selection will depend on being present and making an impression during England camps, rather than reputation or club form alone.
For Palmer, the challenge is to convince the England manager that he deserves to displace one of the players who have retained their place.