Taking to Twitter, Iker Casillas had written in Spanish "I hope you respect me: I'm gay." However, he went on to delete the tweet within hours. and then issued a clarification.
The Spanish legend handed over the first ticket to the 1911 Mohun Bagan captain's descendant.
The former Barcelona captain retired from the game in 2014 after he and Lionel Messi shared six league titles and three Champions League crowns with the Catalan side.
The announcement by the iconic 36-year-old came about an hour after Barcelona announced it had sacked its football director Andoni Zubizarreta who was under contract with the club until 2016.
The 35-year-old has been dogged by injury problems over the last couple of seasons and has only featured four times in the last three months.
Barcelona say Carles Puyol won't travel after picking up a knee injury while Dani Alves is sidelined due to pain in his right leg.
Goals from Neymar and Alexis Sanchez had put Barca 2-0 ahead before youngster Jese Rodriguez netted a late consolation for Madrid.
Neymar gave the hosts a deserved lead with a neat finish from a narrow angle on 19 minutes before Alexis Sanchez sealed the points 12 minutes from time with a delightful chip over Diego Lopez.
Barcelona dropped their first points of the season with a 0-0 away at Osasuna last weekend and were then held 1-1 by AC Milan at the San Siro on Tuesday. Madrid took advantage of that rare slip-up by their rivals with a 2-0 win over Malaga.
Osasuna stood firm to prevent Barca scoring in the league for the first time since January 2012.