Netherlands vs Argentina World Cup 2014: Penalty shoot-out hero Sergio Romero had notes on Dutch players stuffed in his shorts

Argentina goalkeeper clearly did his research as he saved two penalties

Sergio Romero saves Wesley Sneijder's penalty (GETTY IMAGES)

Argentina made it through tot he World Cup final thanks to the heroics of Sergio Romero during the penalty shoot-out against the Netherlands.

But video has revealed the 27-year-old had a hidden weapon in his battle with the Dutch penalty takes: hidden notes on the players.

Stuffed down his shorts Romero consulted the notes as each player approached the penalty area.

The tactic clearly worked as the Sampdoria keeper, who spent last season on loan as Monaco's No 2, saved efforts from Ron Vlaar and Wesley Sneijder.

Argentina scored all four of their efforts past Ajax keeper Jasper Cillessen.

Netherlands manager Louis van Gaal revealed after the game that two of his players refused to take the first penalty that was eventually missed by Vlaar.

Van Gaal was praised for his tactical genius when he threw on Tim Krul in the dying stages against Costa Rica, with the keeper saving two penalties in that shoot-out to see the Dutch into the semi-final.

He was unable to do that this time, however, having used all three of his substititues.

Romero once played under the new Manchester United boss at AZ Alkmaar.

Van Gaal said: "We didn't lose against them, but the penalties are down to luck.

"I taught Romero how to stop penalties, so that hurts."

Former Germany and Arsenal goalkeeper Jens Lehmann revealed he had used notes when he was the hero against Argentina in the 2006 World Cup quarter-final.