Copil began his career at Atletico Arad, and spent time at the Luceafărul București development centre. He came to prominence in December 2006, when it was reported that Liverpool and Celtic were interested in signing him.[2] He was described in the press as "the new Hagi".[3]
Heart of Midlothian won the race to sign Copil, paying a fee in the region of £125,000[4] to secure him to a two-year deal with a further five-year option.[5] His parents were flown over from Arad to Edinburgh to accompany him.
In November 2007 the magazine World Soccer named Copil among the top 50 young footballers in the world.[4] However, he was unable to break into Hearts' first-team and went AWOL in March 2008, returning to Arad after being substituted in a Youth Cup tie.[6]
He was persuaded to return, but told to stay away until pre-season training began in June 2008. The Lithuanian owners of the club suspected that he was only coming back in order to be paid over the summer break.[7] Copil's homesickness and frustration at his absence of first-team football continued in 2008–09, with Hearts' manager Stephen Frail stating that he was not yet good enough to play in the SPL.[8]
Copil left Hearts in January 2009 at the culmination of his initial two-year deal. Hearts had reneged on the five-year option, but offered a one-year extension which they claimed entitled them to a transfer fee when he moved on.[9]
While AWOL from Hearts, Copil had announced his intention to train with Dinamo București,[6] but he rejoined Atletico Arad on transfer deadline day.[10][11] After playing in the first round of the 2009–10 Cupa României for Gloria Arad,[12] he joined UTA Arad on loan.[13]
In June 2010 he was linked with a move to Swindon Town.[13] Swindon distanced themselves from the move, revealing that Copil had been on a week's trial with them in March 2010, but they could not get clearance to play him in the reserves.[14]
Between 2010 and 2013, Copil spent brief periods with various Romanian clubs, before being released by CS Ineu in 2014.
Copil has represented Romania at U-17 level.[15]