Vadillo is considered as one of the most exciting talents in Spain and has drawn comparisons with Cristiano Ronaldo due to his style of play.
The 19-year-old has come through the youth ranks at Betis and became the youngest player to start a Primera Liga game for them when he played against Granada in August 2011.
Vadillo saw his progress held up by a serious knee injury in October 2011, but he is now back to full fitness and a host of clubs across Europe are keeping tabs on him.
Manchester United and Arsenal have held a long-term interest in the Spain Under 19 international, but it is understood that Liverpool and Tottenham are weighing up moves for the skilful wideman.
The likes of AC Milan and Fiorentina are also thought to be admirers of Vadillo with Betis braced for offers for the player during this month's transfer window.
Betis are reluctant to lose Vadillo as they want to keep hold of their best players as they battle to secure survival in La Liga, but would find it hard to turn down a sizeable bid for the winger due to their current predicament.