I am pretty sure it doesn't matter if u do actually touch it....it is your attempt to play the ball.........the 1st most imp. part...is if u are in an offside position.......once u make a move to play it.....the assistant usually raises the flag.........

Chelsea could argue that Ramsey had committed an offside offence by "clearly attempting to play the ball when this impacts an opponent" on the basis that he made a move towards the ball that distracted their defenders and goalkeeper.