The World Anti-Doping Agency's decision to appeal against the verdict rendered by the AFL tribunal on the Essendon 2012 supplements program did not in any way affect Essendon's performance against North Melbourne on Friday, coach James Hird said after the game.

The Bombers lost to the Kangaroos by 11 points at Etihad Stadium, their first game since WADA's announcement on Tuesday.

Hird also provided details of neck injury suffered by forward Jake Carlisle during the week, which left the player with one arm paralysed for half an hour and required hospitalisation.

Hird said he had spoken to his players about the WADA matter on Tuesday. They then met their lawyers on Wednesday, but after that the issue was not raised in team meetings or at training.

"The players didn't really want us to mention it, they want to get on with football and I don't think it had an effect tonight, we were beaten by a better team," he said.

Hird said the players would respond positively on-field to the pressure of the WADA appeal.

"It feels different than what it did the last couple of years, that not-guilty verdict has certainly given them a lot of confidence, so our belief is that we can concentrate on our football," he said.

Hird said Carlisle went for a mark during the last five minutes of the team's Wednesday morning training session, and suffered a small knock to the head which pinched a nerve in his neck.

"He was on the ground for probably half an hour, not moving and had no feeling in his arm," the coach said.

Carlisle was taken to hospital where staff did an MRI scan, which showed there was no spinal damage.

"I think all the players were a bit shocked by that, but luckily he's OK," he said..

The Bombers' starting forward line was young, and was missing key players Paul Chapman, Adam Cooney and David Zaharakis, Hird said.

Tom Bellchambers had fractured the back of his knee in round one against Sydney and Friday was the first time he had played free of pain..

Hird said his team's skills had not been up to scratch over the last few weeks, but Friday's performance was an improvement.

"We played a good team, North Melbourne played well, I thought we had our opportunities but unfortunately (we) didn't take them and probably gave away too many easy goals," he said

North Melbourne coach Brad Scott strongly defended his small forward Lindsay Thomas's ability to draw head-high free kicks, saying anyone who questioned Thomas' approach was "kidding themselves".

"You see a lot of players in the competition who are expert at the technique and the umpires have made it crystal clear that that's the way they are going to umpire the game and the onus is on the tackler," Scott said.

"We get those free kicks against us and we get some for us but anyone who wants to question Lindsay Thomas is kidding themselves and they should question the rule-makers and question the umpires before they question any of our players.

"Lindsay is first for the ball (and) you can't do that if you haven't got the ball in your hands."

Scott said the players were playing to the rules.

"There is no spirit, there is no asterisk that says this is the rule except we would prefer you do this," he said.

"When the tackler gets you high, that's a free kick and if the rule changes we will change, but it is not Lindsay's fault, he is playing to the rules and the way the umpires have told us to play."

Scott praised his players' maturity in winning a game in which they did not play at their best. Drew Petrie had been quiet but moved up the field in the last term to have an important effect on the game.

Scott said captain Andrew Swallow had bruised his hand but would be fine. Forward Ben Brown, subbed out after injuring his reconstructed knee, had not suffered ligament damage to his knee. Brown jarred the knee and, with an interstate trip next week, he would be likely to miss a game.

Forward Jarrad Waite was reported again, this time for a charge in a marking contest.

Scott said Waite jumped early and that got him into compromising positions.