Fremantle star Michael Walters is free to play in Sunday's important home game against Carlton after successfully challenging his one-match suspension for headbutting at the AFL Tribunal.

Walters was reported for headbutting Melbourne's Jay Lockhart during the third quarter last Saturday at the MCG in an incident that the AFL match review officer graded intentional, low impact and high contact.

Fremantle’s counsel, Nick Tweedie SC, successfully argued that Walters pulled Lockhart towards him by the jumper and their forehead contact was incidental from that movement.

Tweedie also claimed the contact was not sufficient to be graded low impact.

The jury deliberated for only four minutes - after a 71-minute hearing - before delivering a verdict the headbutt was not intentional.

Speaking after Tuesday night's hearing, Walters was happy to be cleared and conceded he might need to be more careful when tucking his chin in before physical altercations – a move he learnt from boxing as a child to lower his centre of gravity.

"I'm not a big boy but there is times where I need to watch it in future," Walters said.

"The only reason why I lower my head is to make sure I've got that force as well behind me, otherwise I'm just going to get knocked over."

During a 71-minute hearing on Tuesday, evidence was given from both players and field umpire Curtis Deboy, who believed Walters deliberately moved his head forward to headbutt Lockhart.

He said Lockhart clutched his forehead after the incident and Deboy believed the force was more than negligible.

Also giving evidence by phone, Lockhart claimed he reeled his head back immediately after the incident because he was "surprised and shocked" and denied feeling any pain.

The Melbourne player also said he did not want to see Walters miss a game through suspension, and Walters claimed he was only trying to "chest" Lockhart rather than make contact with his head.

Walters was stunned when Deboy laid the report on the field, saying: "'Are you serious? There was nothing in that.'"

Melbourne's medical report stated there was no immediate treatment required, no ongoing treatment and that Lockhart wouldn't miss any football.

Walters, who is equal 13th in AFL.com.au's Brownlow Medal predictor, remains eligible for the game's highest individual honour after Tuesday's verdict.