PORT Adelaide defender Tom Jonas has been handed a six-match ban for striking Andrew Gaff after the decision to challenge his charge backfired at the Tribunal on Tuesday night.

Jonas received the equal-largest suspension since Dean Solomon was handed an eight-match ban for striking Geelong captain Cameron Ling in 2008.

It was equal to Campbell Brown's six-match suspension for making forceful front-on contact to Adelaide's Aidan Riley in 2012.  

Jonas, who had been referred directly to the Tribunal for his late hit on Gaff, chose to argue his case and sought to have the intent downgraded from intentional to careless.   

He declared he didn't intend to strike Gaff but had been caught in two minds between bracing for contact and attempting to spoil as he closed in on the Eagles' midfielder during last Saturday's clash at Adelaide Oval.   

The defender told the Tribunal he had taken the "soft option" of protecting himself and the forearm he raised was intended to protect his body from impact in the collision.

Jonas will spend seven weeks out of football, with the Power having a bye in round 14, returning against North Melbourne in round 17 at Etihad Stadium.  

"One thing I'm sure of is I didn't intend to make contact with him like that," a contrite Jonas told the Tribunal.  

"I regretted it immediately and I felt terrible.

"It's a little bit embarrassing. I took the soft option and was scared for my own safety. 

"At no time during the incident did I have the intention of striking Andrew Gaff in the neck or head and hurting him."