The former Borussia Dortmund boss says the Champions League winners came to the conclusion that it was “not at all feasible” to sign Haaland over the summer.
Chelsea instead moved for Belgium international Romelu Lukaku for a club-record fee of £97.5million.
Premier League champions Manchester City are interested in a deal for Norway striker Haaland, who is thought to have a release clause of £68m which will activate next year.
Tuchel has not ruled Chelsea out of the race, saying they talk regularly about the 21-year-old at Stamford Bridge.
“We talked about Erling Haaland a couple of times, including during the transfer window. But then it seemed absolutely unrealistic and not at all feasible,” Tuchel told German outlet Sport Bild.
“We talk about him regularly, of course, because he’s a fantastic player and clearly the defining figure at Dortmund, who is a big rival for us in the Champions League.”
The Chelsea boss was also asked whether the signing of Lukaku prevented any future move for Haaland and responded by saying: “You mean two at the top [with] Lukaku and Haaland? We can talk about it [laughs].”
Despite his joke in response to the question, the German manager certainly left the door open for a move further down the line.
“I don’t think we’ve been really serious about it yet,” said Tuchel. “But let’s see what will happen in the next few weeks.”
Haaland has 13 goals in 10 appearances for Dortmund so far this season and boasts a remarkable record since joining the German club from Red Bull Salzburg, with 70 goals in just 69 outings overall.