Barcelona's most famous street Las Ramblas was packed with tourists when a van drove into the crowds, leaving scenes of carnage.
With Neymar already being the third best player in the world, if he could step his game up to near Ronaldo and Messi's level for goals and assists this upcoming season, he could overtake the two veterans at the top of the game. A fifth died a few hours later.
Moments after the attack, Spanish Sportstars, including Messi and Ronaldo, came forth to condemn the attack.
The Real Madrid and Barcelona stars head the shortlist for the FIFA World Player of the Year.
Messi took to Instagram on Thursday night to express his shock and sadness at the attack.
But pre-season is now over and Barcelona are yet to make a further announcement to confirm that the five-time Ballon d'Or has signed the new deal.
He wrote: "I would like to send my condolences and all my support to the families and friends of the victims of the awful attack on our beloved Barcelona, as well as totally reject any act of violence".
Real Madrid, who had beaten Barca on Wednesday to win the Spanish Super Cup, issued a statement saying that the club "stands together" with the victims and their families and friends.
The football world has united in paying tribute to the victims of Thursday's Barcelona attacks which killed 14 people and injured at least 100. "All our thoughts are with the victims, their families and with the people of Barcelona". "As a mark of respect, the flags will fly at half-mast at the club's installations and the players from both teams will wear black armbands in all the club's matches this weekend", the club said in a statement.