Walcott's pace terrified Barcelona and Premier League defenders!

Theo Walcott is the fastest footballer we have ever seen. The most terrifying thing for any full back is coming up against genuine pace.

The movement that really scares full backs is when a winger looks to go long; when they play on your shoulder and midfielders try to play the ball in behind.

Against Arsenal - with Walcott - most teams drop deep on to the edge of the box, so that negates the threat of his pace, so the ball can't as easily be slipped in behind the back four.

On Wednesday, Barcelona played higher up the pitch to try to win the ball in the home side's half. By doing that, they created space in behind for Walcott to exploit, and he did just that with his goal. The winger benefited from their approach at the Emirates and next week at the Nou Camp he may force Barca to change their game plan entirely.

Theo's an immense talent but he's very young and still learning his game. He's always relied on his raw pace and will continue to do so but as he gets older he will learn when to use it best.

The pace of Theo Walcott caused all sorts of problems for left back Maxwell but the Barcelona star's approach to defending against him was a large part of the problem. When you're defending against raw pace, it is suicidal for the left back to leave a big space between him and his centre half, as Maxwell did night.

That meant that Abou Diaby could intercept a pass from Sergio Busquets and feed the ball to Samir Nasri, who in turn passed to Nicklas Bendtner. The Dane was able to play the ball through that gap as Walcott raced around the outside of Maxwell - at a top speed of almost 23mph - to get to the ball first.

If Maxwell had closed the gap, Arsenal would have had to give Walcott the ball in front of Maxwell and he would have had to beat him to cause any damage. But what Barcelona soon realised - and this is the best way to defend against pace - is that if they stopped the ball being fed to Walcott, he couldn't hurt them.

As soon as Barcelona started closing Diaby down, he couldn't play that ball and Walcott's influence on the game waned.