Champions League semi-final second leg for Chelsea against Real Madrid.
Havertz scored twice for Chelsea in the 2-0 win over Fulham at the weekend, and kept his place in the starting XI with Pulisic restricted to a place on the bench.
Tuchel was asked about Havertz giving him a “positive headache” with his recent form, and the manager agreed.
“For him in a good way,” Tuchel told BT Sport.
“Christian got a bad message for him today unfortunately, but I’m pretty sure we need more than 11 players to sneak through today.
“It’s good to have Christian from the bench. Kai gives us a little bit of height also against the set-pieces and maybe in fast attacks can keep the ball.“
Tuchel said that Chelsea needed to trust in themselves ahead of the game and hope to catch little bits of luck during the encounter to ensure they deliver “a performance on the highest level”.
“I don’t think we need a miracle or any crazy stuff, but we need our best level of performance, this is clear,” Tuchel added.
“We have trust in ourselves, we arrive self-confident for this match and this is the best way to arrive. Then you have to prepare for any questions and we face a difficult team from Real Madrid with a lot of quality.
“As you know, you need a little bit of luck, a bit of momentum; maybe the little decisions and little situations that can decide matches like this.
“What we want from us is a performance on the highest level. We are used to giving that normally.”