St Kilda’s Jimmy Webster was banned for seven matches by the AFL Tribunal on Tuesday – the longest suspension handed down in six years.

Webster’s shoulder to the head of Jy Simpkin left the North Melbourne star suffering concussion during a practice match on Sunday.

In a landmark case that puts down a new marker in the AFL’s bid to protect players from concussion, Webster pleaded guilty and threw himself at the mercy of the tribunal.

The AFL argued for an eight-game suspension, which St Kilda believed was “excessive and disproportionate in the circumstances”.

The Saints pleaded guilty and Webster said: “I’m really sorry about what happened on Sunday. It’s something I’m not proud of – I’ve left a lot of people down.

“My main concern is for Jy to get back to playing footy and I really hope he’s OK. I understand how bad concussions are and how much we want to see them stamped out of the game.”

Webster was asked why he had jumped off the ground and replied that he didn’t have an excuse.

He added he was “sick about” the incident, which he hadn’t watched until the hearing. But he added he was concerned about how the incident and the fallout was affecting his family.

“I’m happy to cop the backlash, but I’ve got a 16-month old and a wife at home. For them to cop it on social media, it’s obviously pretty shit,” he said.

Andrew Woods, for the AFL, described the hit as “at the higher end of carelessness”.

“Intention isn’t alleged but a clear decision was made to leave the ground and tuck the arm in. It’s very significantly careless given his speed and player Simpkin’s momentum,” said Woods.