Former Hawthorn premiership player Brad Sewell has opened up about that infamous incident involving Essendon's Matthew Lloyd.

It was the last round of the 2009 season, Sewell received a crunching hit from Lloyd that ultimately fractured the Hawks midfielder's jaw. Nearly a decade on from the hit, Sewell has stated how the twilight of his football career suffered as a result of the concussion.

"It was the last game of the year so I didn't miss any games per se but I sort of felt like I didn't get back to playing good footy until 12 months later," Sewell told SEN radio. 

"Obviously I played that following year in 2010 but I didn't feel like the same footballer for one reason or another for quite some time thereafter."

Sewell managed to escape any serious or ongoing issues following the knock, something that doesn't happen as regular to players who have been treated for concussion following retirement.

"That was obviously a serious concussion but otherwise I escaped relatively unscathed. I think that was the only concussion I had," he continued.

"I didn't have any lingering effects and certainly don't to this day. I guess that's the risk or the challenge for today's players and the medicos because you just don't really know do you?

"It's one of those things, concussion and the after-effects, that we just don't know enough about."

Sewell was adamant that he hasn't held any sort of grudge towards Lloyd, and feels he didn't do a whole lot wrong.

Essendon and Hawthorn will do battle Friday Night at Marvel Stadium in a rivalry that has spread across several decades.