Alvarez lost his lightweight title to McGregor at Madison Square Garden.
McGregor will be out of action for at least six months.
Conor McGregor revealed that he will take a break following his win over Eddie Alvarez.
UFC 205 event took place in New York's Madison Square Garden.
Nurmagomedov beat Johnson via submission at the UFC 205 event in New York.
Lee admitted that it was frustrating to watch Alvarez's defeat at McGregor's hands.
Conor McGregor has challenged Floyd Mayweather again after recent comments by the boxer.
Mayweather had previously shown interest in fighting McGregor.
McGregor created history after he became the first fighter to hold two UFC titles.
McGregor is taking some time off from the sport to be with his family.
'He's got the personality, the skills, the talk. He's an entertainer, for sure,' Triple H said.
McGregor is expected to become a father early next year.
Madonna and the Logan actor were joined by other celebrities including Zac Efron at the UFC event.
Undercard round-up: Khabib Nurmagomedov demands shot at Irishman after submitting Michael Johnson.
McGregor knocked out Eddie Alvarez in the second round at UFC 205.
Irishman becomes the first fighter in UFC history to hold two world title belts concurrently.
Conor McGregor and Eddie Alvarez will face each other at UFC 205 on 12 November.
Miesha Tate will face Raquel Pennington on Saturday.
The Irishman is aiming to become a double UFC champion.
Alvarez and McGregor will face each other at UFC 205 on 12 November.
McGregor was fined for his pre-fight conference antics ahead of a fight against Nate Diaz at UFC 202.
McGregor is looking to become the first UFC fighter in history to hold two-weight titles.