The Spaniard joined the La Liga side on loan from Chelsea in the summer, but struggled with a succession of injuries in the early part of the campaign.
However, the 22-year-old midfielder has played his way into the side in recent weeks with impressive displays against Swansea City and Osasuna.
"I've been a while waiting and working hard and I'm happy the manager has given me the opportunity. My aim is to keep working hard. The team looks really good to me right now. The results haven't come by chance and I'm amongst the first to be happy about that," he told reporters at a press conference.
"When you come back from an injury you can be a little bit green and it can be difficult to get the confidence back, but in time the pressure falls away.
"In the game at Swansea I did well and my teammates helped me a lot, because there's a lot of good football played in this team."
Romeu came through the youth ranks at Barcelona.