Kanpur: Gambhir has been given permission by the Indian cricket board to attend his sister's wedding, which falls on the second day of the Test opening at the Brabourne stadium on Wednesday.
India were grappling with a new selection headache on Saturday, with in-form opener Gautam Gambhir opting out of the crucial third Test against Sri Lanka in Mumbai.
Gambhir's absence is likely to throw India on the back foot as they seek to win the three-Test series, which they lead 1-0 after their innings and 144 runs victory in the second match here on Friday.
The opening Test in Ahmedabad ended in a draw. A 2-0 series win will put India on the top of the Test rankings and also deny Kumar Sangakkara's men their maiden victory on Indian soil in the longest version of the game.
Gambhir, 28, has been enjoying a golden run with the bat, having hit four centuries in a row in his last four Tests, including knocks of 114 and 167 in the current series.
Sri Lanka tour of India - Fixture - Top 10(R/W) - Results
It was his vital 233-run opening partnership with Virender Sehwag in the second Test which laid the platform for India's massive victory.
In his last 25 innings, Gambhir has hammered seven centuries and seven half-centuries for a stunning average of 77. Overall, he has scored 2,553 runs from 27 Tests since making his debut in 2004.
India's captain Mahendra Singh Dhoni was measured in his response when asked about Gambhir's unavailability.
"It's difficult to say how much the team will miss Gambhir," Dhoni said. "There are times when you have to adjust to situations. These are things we cannot do much about.
"We are a side that depend a lot on good starts and whoever opens with Sehwag should be able to do that."
The Indians have a reserve opener in their squad in Murali Vijay, who has played only one Test, against Australia in November last year.