Adelaide coach Brenton Sanderson says Crows, Bombers players are guinea pigs for new contact below the knees rule Adelaide's Brent Reilly crashes into the legs of Alwyn Davey, giving away a free kick. Picture: Simon Cross Source: Herald Sun ADELAIDE coach Brenton Sanderson says it is impossible to change players' instincts to try to win the ball even if it means giving away a free kick. But both Essendon coach James Hird and his Adelaide counterpart Brenton Sanderson say it will take players time to adjust to a law change which is changing a fabric of the game. The rule penalising players who slide into an opponent's legs was prevalent as Essendon won the season-opener in Adelaide on Friday night by 35 points. Sanderson says his Crows players battled to adjust to being "guinea pigs" for the new rule. Adelaide defender Brent Reilly conceded a goal from the law change: despite collecting the ball, he was penalised for cannoning into the legs of Essendon's Alwyn Davey. Sanderson said Reilly wouldn't have given away a free kick for doing the same thing last year. "It's a tricky one because it looked like Radar (Reilly) was going for the ball," he said. The interpretation of the new rule is that is now a free kick but we get penalised with a goal against. We will have to have a look at that and show the players. I guess everyone now across the competition gets a first look at the guinea pigs - Essendon and the Crows will be the benchmark now for what that rule is. And it will be scrutinised pretty heavily throughout the media this week. Sanderson said it was impossible to change the instinct of players to dive to win possession of ground balls. "You can't change instinct, you have to teach better method," he said. But Bombers coach James Hird said the new rule was well handled by players and umpires. Watson inspires Bomber victory "We spent a bit of time since our last NAB Cup game against GWS practising some things, not to get a free kick, but to avoid a free kick - the way we tackle, the way we go for the ball and that has certainly helped us," Hird said. It will take a while for players to get used to it and also for umpires to get used to it. I thought it was handled very well by the players and the umpires but that is probably a biased point of view because we won.