Chelsea defender Gary Cahill has expressed dismay at the 'crazy' offside rule that allowed Alexis Sanchez's opening goal in the FA Cup final stand.

The Chilean put the ball in the net in the fifth minute of the game with his Arsenal teammate Aaron Ramsey in an offside position.

"That offside rule is a crazy rule," said Cahill following the 2-1 defeat to the Gunners at Wembley Stadium.

"You can look to go to the ball and veer off and then not be ruled offside. It is the maddest rule I have ever seen.

"If he [Ramsey] is not there, then maybe our goalkeeper Thibaut Courtois comes out and grabs the ball.

"The handball decision is the most annoying because if that had been given it would not even get to the offside decision.

"If he [Sanchez] gets the ball and has his hands in a natural position down by his side, I understand that. I understand it is difficult when the ball ricochets and it is not your intention to touch it.

"But when you have both hands above your face, you are not telling me that is a natural position.

"It was incredible. I spoke to the referee at half-time and he was adamant Sanchez kneed the ball through. We saw it differently. We were very unlucky."