The Australian goalkeeper let an Alexis Sanchez shot squirm over the line in their 2-1 defeat to Arsenal in the semi-final which ultimately denied his side a place in the Wembley showdown on May 30.
Sky sources understand the 30-year-old, who was left in tears at the full-time whistle as the Royals missed out on a place in their first FA Cup final, would have rearranged his wedding, had Reading won.
Sky Sports reporter Dharmesh Sheth said: “It emerged in the newspapers that the Reading goalkeeper (Federici) was having his wedding, and it was planned on cup final weekend.
“I did speak to the club, and the wedding was indeed planned, but 18-months to two years ago.
“If Reading had reached that final there is no qualms it (the wedding) would have been rearranged and Adam Federici would have been playing for Reading.
“But as it is, he’s got another important match up on cup final weekend – his wedding.”
Federici, who has spent 10 years with Reading since joining from Sardinian club Torres, will marry long-term girlfriend Micaela Gardner in Italy.