Having arrived in Gorgie 12 and 18 months ago from Romania and Bulgaria respectively, the youngsters were reckoned to be among the most talented of their generation. Copil, in fact, was even named among the top 50 prospects in Europe by respected magazine, World Soccer.

However, the precocious teenager has walked out on Hearts and returned to Romania after taking umbrage at being substituted during Hearts' recent Youth Cup defeat by Rangers.

Kostadinov, meanwhile, has spent the past week on trial at Manchester City, a club who rejected the opportunity to sign him as a 15-year-old. Now 19, the former LASK Linz left-sided midfielder or striker travelled south after being recommended to the English Premier League club by his father, Petio, a licensed agent who has recently taken control of his son's transfer affairs. Despite never having featured for the Hearts first team, Kostadinov believes his son is already destined for bigger and better things. "Petio thinks his son is a world-beater," said one onlooker.

Kostadinov Snr, moreover, is known to be a close associate of Anatoly Korobochka, Hearts' sport director; Korobochka gave his blessing to the Manchester City trial despite the fact that John Murray, Hearts' youth academy director, and Darren Murray, the Under-19 coach, have no desire to see the player leave the club.

Copil's case is more intriguing. Known to be from a particularly poor family in the Romanian town of Arad, Hearts paid ?200,000 for the right-sided midfielder's services, after beating off interest from Celtic. Like Kostadinov, he has failed to trouble even the first-team substitutes' bench this season but Copil has cut a disconsolate figure in recent times, making it clear to those around him that he is unhappy with life in Scotland.

Now back in his homeland, Hearts have informed the player that he has been fined for leaving without permission. There is no suggestion that Copil plans to rejoin the Tynecastle club in the near future.

Copil is understood to have returned from a Christmas break in his homeland with an injury, sustained while playing football with friends. He was escorted back to Scotland after the holiday period and subsequently home within the last fortnight by his mother, Florica, who cannot remain in this country for longer than three months because of work permit regulations.

Hearts retain a five-year contract option on Copil, but even if that deal is not invoked by the club, they will be entitled to compensation for the player should he look to move elsewhere. Speculation in his homeland has linked him with a move to Steaua Bucharest, who along with Celtic, had courted him before he joined Hearts. Those close to Hearts, however, have stressed that the club have done everything possible to allow Copil to settle in Scotland.

"John Murray and Hearts could not have done more for Copil," said a source close to the player, who added that the academy director has gone so far as to buy a laptop computer and boots for the youngster from his own pocket. "He is regarded as the most talented kid at the club, he has been lifted and laid and wanted for nothing, but he has thrown all Hearts' help back in their face."

Both Copil and Kostadinov joined the full squad for pre-season in Germany last year but went back to general apprentice duties on their return, such as cleaning the boots of senior players, which is understood to have riled the Romanian.

Amid such discord, the chances of Hearts' supporters seeing two players – whose arrival in the capital was much heralded – turning out in maroon are growing ever-more remote.