The Spain midfielder came on for David Villa just before the break and was again outstanding playing just behind Fernando Torres and then Dani Güiza against Russia.
"I really do not know," he told ITV. "You will have to speak to the coach."
La Furia Roja qualified for their first championships final since 1984 thanks to goals from Xavi, Güiza and David Silva and Fàbregas was only thinking about enjoying the celebrations.
"It is good. We came here to win the tournament. We have reached the final, which was always the most difficult thing," he continued.
"In the final anything can happen. There are a lot influences. Right now we have to enjoy tonight and think about the final later."
Fàbregas then revealed that he was not told what his role would be in detail by Luis Aragonés given the short time he had to prepare.
"He told me nothing, there was not time," he stated. "It was a tactical switch. I am not a striker, but I played like a second striker when I went on.
"Then when it settled down we all went forward. David Silva, Xavi and Andrés Iniesta and myself all moved up and we did well."
Was it the best game of hs life? "Maybe, but I'll have to watch it on video again to have a better opinion," he said, before modestly playing down his impact on proceedings: "I don't think I changed the game though when I came on, I just played the way I could."
He described the significance of the final penalty that brought Spain through to the semi-finals in the shootout win over world champions Italy: "It was a defining moment, one of the most important of my life. Everything went well, it could have gone wrong."
Cesc is now eager to make history, with Spain having only won this (or any) competition once before (44 years ago, in its second ever edition) and haven't been in a final since 1984.
"History is waiting for us, hopefully! We'll have to try to play our best game of the tournament (against Germany)," he continued.
"The Germans are very experienced and very competitive but if we play like we did tonight we have a good chance."
He had praise for Germany's man of the tournament so far and Premier League rival, Chelsea's Michael Ballack: "Ballack's doing an amazing job for Germany and for me he is one of the players of the tournament."
The key to Spain's success? "We forged this team spirit in qualifying. There's always this doubt in Spain. We've got through the semi-final and now the final but no one was expecting us to be where we are now.
"We've displayed great mental strength, that's the key."
Lucas Brown, Goal.com