But Newcastle boss Glenn Roeder insists Albert Luque is close to fulfilling his potential as a Premiership player.
Roeder: "It's been difficult for him in England, starting badly with a very nasty torn hamstring.
"His English has improved a lot which I hope will help, he's got to show that he's now adapting to life in the Premiership. It is high tempo from the first to the last minute. La Liga, where he has been successful, is one of the strongest leagues in football, but the tempo is not so high.
"In the Premiership, the quality of fighting, of aggressiveness is so important. It's not just competing with your opponent, it's running. You've got to run aggressively and with urgency at all times.
"Anyone should be able to do that. The technical side of the game is why these top players earn so much money, but the two things must go together.
"Technique alone is not going to give you a career in the Premiership. It might in other leagues, but not here. The two things go hand in hand; the aggressive running has to go with the technical ability and football knowledge.
"There is no one here who would accuse Albert of lacking technical ability. He has got that Spanish ability to control and pass the ball, shoot and head as a striker. He very rarely mis-controls the ball, but we need to see that aggressiveness as well, to run and work, not just for himself, but for the team."