Watford boss Quique Sanchez Flores is concerned over delays regarded Fran Montavez's transfer from Real Madrid.
Montavez, 19, joined from Real Madrid at the start of the season in view of being part of Flores' future first-team plans.
The Mirror says Montavez has yet to play competitively as he is still waiting for clearance - two months after his arrival.
The Spanish FA must rubber stamp the paperwork before Montavez is eligible to pull on a Hornets shirt.