The midfielder started his first game for the club in a Carling Cup second round tie at Southampton on August 25 and has been in and around the squad for most of the season to date.
He said: "It's been great, I love it. Since I went over, everything happened so quickly, and I made by debut quickly enough as well, and that helps.
"I have been playing the Carling Cup games and on the bench nearly every week, so it's going really well. I am enjoying it, enjoying every minute.
"The week I signed, the manager came out and said, 'He's not one for now, he's one for the future'.
"To be fair, that's what I thought when I was going over anyway. I knew I would have to work hard because of the quality of the players who are there.
"I was shocked when I was in the squad and then playing, and I have been in nearly every squad so far."
But it is international football which currently concerns O'Shea, 21, as he and his compatriots attempt to re-ignite their European Under-21s Championship qualifying campaign against Georgia at Tallaght Stadium tonight and Switzerland in Waterford on Tuesday after taking just one point from their first two games.
He said: "There are great players in the squad and we have been playing really well.
"We have been playing good football and if we take the chances we have been creating, we will be a great team."