Timo Werner also earned Tuchel’s praise after setting up Havertz’s second goal, while Hakim Ziyech was unfortunate to miss out on the first leg in Madrid last week.
Chelsea’s manager is still to come up with the right balance up front – but Havertz is increasingly establishing himself as the best option in the middle of an attacking three.
Deploying Havertz as a false nine would rob Ramos of a direct opponent to engage with.
Discussin his options, Tuchel said: “Maybe play no striker at all then Ramos has nothing to fight against. That can also be a solution.
“I have not made my mind up yet. Let’s wait until (we know) he is fit. If he is fit, it is another challenge because he is the leader of the group and he is the guy to give a lot of solutions to any question that we will hopefully ask them.
“Let’s wait and see who is in good shape, in good form and what shape we play and where we try to hurt them. I am not so sure that they will play with five or go back to four. There are many questions and the don’t have the answers now, we will see on Wednesday.”
He looks certain to retain his place on Wednesday, with Werner or Christian Pulisic missing out.
Tuchel was full of praise for Havertz after his strikes in each half kept Chelsea on course for a top four finish.
“Still there is room for improvement, but for today I am very happy,” he said. “Of course, he was decisive, he was involved with Timo as a double striker and with Mason and Hakim as the four offensive guys, always involved in dangerous attacks and situations.
“For me it was the individual example for what I just explained, the players today who maybe had a tough decision on them last Tuesday, but they didn’t say, or like Kai today, didn’t play with the attitude that ‘They need me and I wanted more time in Madrid, why do they play me now only against Fulham.’
“This was absolutely not the case, he took his chance, he showed up, this is what we need all the time and especially in situations like this, you need guys who are fully committed. That means if you have a chance to show up, then show. If you have five minutes, 15 minutes or a whole game, whatever it is, show that you are ready and give me a headache for the next game.
“He did that and it is an example for what the whole team did and they get full credit from me.”
Mateo Kovacic is facing a race to be available on Wednesday.
The midfielder has suffered a setback in his recovery from a hamstring strain.
Antonioi Rudiger has returned to training after suffering knock to face in the final moments against Real and could have to play with a mask.
Tuchel added: “He trained today with a mask so it is just about getting used to it. For Kova it will be very tight because he had a little setback, he felt something around the muscle area – not the same area, not the same muscle, so I think it will be a very tight race for him. It is very likely he will not make it, unfortunately.
“We are absolutely in the place in which you want, in the situation in which you want to arrive in a crucial match like this on Wednesday. Unfortunately we miss Kova and we have some doubts with Toni.
“I am very sure everybody will be totally focused from Monday on. We have two training sessions Monday, Tuesday to prepare for Real Madrid. So it will be exciting.
“I am very happy to arrive with this group in the semi-final. We feel ready for a big fight and I am sure that we need a big performance and Real Madrid will give us a hard match.”