He previously played for RC Timişoara, and made his European debut season in the 2005/2006 season as Bucharest played in the European Challenge Cup. Having scored a try in his first season better was to come in his second year in Europe scoring six tries in the group stages a great achievement however it was not enough to get Bucharest through their group and this prevented Fercu from potentially being the tournaments top try scorer. Such notable achievements in the 2006/2007 European Challenge Cup include a hat-trick of tries against French side Bayonne.
Fercu has also already made appearances on the international stage even at his young age and he played against France and Scotland in the Autumn internationals in 2006. He also scored a try against the French. Fercu helped guide Romania to the 2007 Rugby World Cup as he played in the qualifier matches including the vital games against Georgia and Spain and scored a try against Spain in the game that sealed their qualification to the Rugby World Cup.
Fercu was a late withdrawal from their Rugby World Cup squad because he was not prepared to fly all the way to New Zealand. The Romanian side arrived in Christchurch to prepare for their first game of the tournament against Scotland in Invercargill on 10 September without Fercu, who failed to get on the plane when it left Romania.
Fercu has been a Saracens player since October 2014. He played in the winning Aviva A League Saracens Storm team, as well as for the Saracens LV Anglo Welsh Cup winning team. He made his debut in the Aviva Premiership during the match Saracens - Harlequins (42 - 14) at the Wembley Stadium on 28 March 2015, in front of world record breaking assistance of 84,068.