Royals took the Premier League giants to extra time after an Alexis Sanchez opener had been cancelled out by Gareth McCleary, whose shot was fumbled by Gunners stopper Wojciech Szczesny.

But Arsene Wenger’s men were gifted a 2-1 lead in the 105th minute of a pulsating cup clash when Federici allowed a tame shot by Sanchez to squirm through his legs and into the net.

Holders Arsenal saw out the remainder of the game to deny Reading a place in the club’s first-ever FA Cup final.

Royals boss Steve Clarke admitted Federici was ‘distraught’ when the final whistle blew and the Australian star left the Wembley pitch in floods of tears.

However, the 30-year-old, who had made a string of brilliant saves throughout the semi final, has received overwhelming support from Reading FC fans all over the world since his error on Saturday.

Federici took to Twitter this morning to finally break his silence from his @Federici32 account.

He said: “Just like to say thank you for all your messages and how sorry I am for my mistake, we gave our all and deserved to at least take it to pens.

“It’s part of being a goal keeper and I’m sure it will make me stronger! Thank you again for your amazing support #readingfc.”

Royals fans are now planning to turn Wednesday’s Championship home fixture against Birmingham City into a huge show of support for Federici.

A campaign called #FlagsForFeds has been launched on social media urging spectators to take Australian flags with them to the match at Madejski Stadium (8pm ko).

The initiative has been backed by Royals’ fans website, The Tilehurst End, as well as the Supporters Trust at Reading (STAR).

Federici is a leading candidate to win Royals’ Player of the Season award at the end of the campaign.

He made some brilliant saves during Saturday’s semi final including an incredible effort to deny Gabriel in the second half.

Reading FC teammate and fellow Aussie Ryan Edwards tweeted: “So much love for @federici32! Always come back stronger, an inspiration to me! #togetherstronger #aussies #readingfc.”

Gunners keeper Szczesny suggested his Reading counterpart was arguably man-of-the match on his @13Szczesny account. “He was the best player on the pitch,’ he tweeted.

Arsenal fan Piers Morgan, who was at the game, also tweeted: “You had a great game @federici32 - don’t beat yourself up too much about the mistake. I’ve done far worse.”

Nevertheless, Federici’s future at Reading FC remains uncertain as he is one of eight first-team players whose contracts are due to expire this summer, and he has not been offered a new one yet.

The Australian was linked with a move to Premier League Southampton recently and Clarke confirmed on Saturday that Federici’s contract situation is out of his hands while the club continues to balance the books.