Chesterfield have signed teenage defender Janos Kovacs from Hungarian club MTK Budapest KFT. There is no fee involved for Kovacs, 19, who has signed a two-year deal.
However, Kovacs will return to his old club in 2007 unless a further agreement is reached - while both clubs would benefit from any transfer offer.
"Jason showed enough in pre-season to suggest he could have a good future in the game," Spireites boss Roy McFarland told the club website.
"We are really pleased that he has decided to join us, and also that his home club in Budapest have been willing to sanction the move."