Complacency started to seep into his game after half-time, with some misplaced passes but it was an overall impressive performance for the Dane - something he really needed.
And the Italian did himself no harm with a good performance against Forest. The latter struggled during the match against Chelsea but could not fight to qualify for the fourth round.
It looked like Fabregas would crown his final game with a goal wehn Ruben Loftus Cheek was brought down in the box in the 30th minute.
"He has got everything to make it in world football", the Spaniard added.
Alvaro Morata appeared to confirm Fabregas would leave Chelsea on social media, writing on Instagram: "You do not know how much I'm going to miss you!"
Chelsea fans will be used to seeing Ethan Ampadu playing in defence but for Wales the teenager has often featured in midfield.
With reasoning based on the rise of Jadon Sancho at Borussia Dortmund, former footballers in broadcast studios seem certain the 18-year-old Hudson-Odoi would have more opportunities to develop in Germany.
Luiz also opened up on how he will remember Fabregas as a "world-class" talent. He's certainly no Kante yet, but the Welshman may just have shown Sarri he can be an adequate back up.
Callum Hudson-Odoi chose the day Bayern Munich manager Niko Kovac confirmed his interest in signing the teenage striker to display for a wider audience what all the fuss is about.
Chelsea's starting eleven to face Nottingham Forest confirmed.
The 31-year-old captained Chelsea against Nottingham Forest on Saturday, in what was likely his final appearance after four and a half seasons with the Blues.
He scored two goals, both after assists from Hudson-Odoi, and he hardly celebrated them.
"The occasion got the better of me", Fabregas told BBC Sport.