In the editor you can make a player homegrown with one of his options in his profile, or use a hand of god to heal someone.
You can also try going on holiday for a couple of days and let your assistant deal with it . You can also try going into your previous save game and fixing the problem before the match begins. GL
FYI the rules are:
UEFA defines locally-trained or 'homegrown' players as those who, regardless of their nationality, have been trained by their club or by another club in the same national association for at least three years between the age of 15 and 21. Up to half of the locally-trained players must be from the club itself, with the others being either from the club itself or from other clubs in the same association. http://www.uefa.com/news/newsid=943393.html
Premier League definition:
A home-grown player will be defined as one who, irrespective of his nationality or age, has been registered with any club affiliated to the Football Association or the Football Association of Wales for a period, continuous or not, of three entire seasons or 36 months prior to his 21st birthday (or the end of the Season during which he turns 21).