Oxford have signed Dundalk striker Patrick Hoban on a free transfer but he will only be available from 1 January.
The 23-year-old was joint top scorer in the League of Ireland Premier Division with 20 goals for champions Dundalk, and also netted away to Hadjuk Split in the Europa League.
He began his career at Mervue United and also played for Bristol City.
Hoban has signed an 18-month deal at the Kassam Stadium, with the club having the option of a further year.
"I want to prove people wrong and show I can play over here," Hoban told BBC Radio Oxford.
"I'm very ambitious. I like to set the bar high. It was a good season for me personally and the squad so I'm absolutely delighted to be here."
Hoban admitted it was frustrating to have to wait nearly six weeks to make his debut, because of international transfer windows, but says he is excited by the challenge awaiting him at the Kassam Stadium.
"It's frustrating, you just want to play football. You miss it after a day so I'll have to wait and get myself ready for 1 January," he said.
"Oxford were the most interested, they came to watch me play. Oxford are appealing as they have quite a bit fanbase, the manager sees me in his plans so that is why I came here. I'm looking forward to the challenge big time."
Hoban, who did not play a game for Bristol City and was released in 2011, turned down a trial at Scottish Premiership Kilmarnock earlier this month.