Now it is just a question of whether he will be playing or watching from the stands.
The 22-year-old has just three first-team games to his name but the most recent was the Royals' 1-1 draw at Manchester United, with the two sides meeting at the Madejski Stadium on Tuesday night to decide battle for a quarter-final place.
The Australian pipped Robbie Keane in a Football Association poll to decide on the fifth round's best performer and that meant tickets for the finals are now his.
He said: "Hopefully I will be playing in it, that's my first goal. I thought Robbie Keane deserved it more, he scored a couple of blinding goals so I was very lucky.
"There were even some better saves throughout that round. It was just because we were playing Man United that they were picked out, but it feels good."
Federici admits Sir Alex Ferguson's side will remain favourites on a night when both sides are expected to make wholesale changes from their normal Premiership selections.
But he is confident that whoever Royals boss Steve Coppell picks will be able to pull off the win a capacity crowd craves.
He said: "We believed fully when we went up there that we could have beaten them and we have a better chance now.
"We will be underdogs again but that's all right with us because it gives us nothing to lose.
"Man United are sick of seeing us this season and won't be looking forward to coming down again to the Madejski.
"We went up there and did well so we have got to be confident in ourselves. I think we can cause an upset."
Federici became Marcus Hahnemann's understudy in October when Graham Stack went on loan to Leeds and Coppell's policy of playing fringe men in cup games meant he was finally able to play a first-team game in England in the third-round victory over Burnley.
The Australian revealed he had fought long and hard to get this far.
He added: "I went to a lot of clubs and knocked on a lot of doors but no-one wanted to take a chance on me.
"I was just a boy from Jervis Bay, a little town 90 minutes out of Sydney, and all I was asking was a chance to play. It took three years.
"I only unpacked my suitcase last season when I got my professional contract and I was on Ibrahima Sonko's couch for a while.
"I was 17 when I first came over and had a trial with Bolton. That didn't work out so I was writing letters and just turning up at clubs' doors.
"I had a resume I sent to every club and a little video I had made of games in Australia. A lot of clubs gave me trials but they all said the same thing - I was good enough but they couldn't take the risk, which was fair enough."
Eventually Reading decided to give him a chance and Coppell has been so impressed that he has suggested future international honours will not be far away.
Defying United remains the most immediate priority and Andre Bikey is set to replace the cup-tied Michael Duberry in defence, with striker Kevin Doyle likely to start on the bench following a month out with a hamstring injury.