The visitors completely dominated at Old Trafford, with Havertz having a hat-trick of chances in the first half.
But it was up to Marcos Alonso to fire Chelsea on the hour mark – only for Cristiano Ronaldo to level the scores with a superb strike.
Tuchel insisted there was no blame on Havertz but called on the striker to rediscover the form that saw him edge ahead of Romelu Lukaku when Chelsea attacked.
“He has to fight and get his form back and I hope he shows a reaction,” he said after the game. “The guys are still young up front and we won’t start pointing fingers.
“Lately they’ve been very quiet and taking their chances. When we look at the data and who’s playing, we see a huge amount of sprints and intensity from Kai and Timo [Werner] and that is why we protect them.
“Over the last few weeks he had kind of a shape and form where he would have put the game to bed.”
Tuchel admitted his team missed the chance to collect the three points.
“We were very strong on and off the ball, very dominant on the ball, very aggressive, lots of won balls, lots of half chances,” he said.
“But, unfortunately, we lacked precision in the area, a little determination to finish it, at the start of the match, but also throughout the match and unfortunately we had it and we gave it in one minute.
“I was very happy with the way we played. We found enough space to enjoy it more. It seemed to me that he lacked a bit in the last 16 meters to finish earlier.