RILEY BONNER thought his day was done. 

A punishing two-and-a-half-hour training session for his AFL club Port Adelaide had pushed him to the edge of his physical limits. 

But a tap on the shoulder from Chad Cornes, the Power's then-SANFL coach and a 239-game club great, stopped Bonner in his tracks as his mind and body prepared to wind down. 

The young defender's torture had just begun as he was introduced to the infamous 'Cornes Drill', where he had to try and beat Cornes to a series of ground balls. 

Cornes proceeded to taunt and sledge Bonner as he denied him possession. 

This became a post-session ritual for the West Adelaide and Goodwood Saints product, who also completed the drill with another former Port Adelaide footballer, Jacob Surjan. 

The Power's 2004 premiership coach Mark Williams used to subject Cornes to the same torment, hence it being named in his honour. 

"It was one of the most gruelling things I've had to do," Bonner told AFL.com.au. 

"Chad wouldn't let me get the ball. It was at the end of pre-season training and he was trying to mentally break me. 

"It was tough at the time, especially being not as physically developed as I am now, but I got through it and it's helped me. 

"I'd be last on the track, but I loved every bit of it. As much as I hated doing it, I knew they were putting the work into me for the long run, and I can't thank them enough for their time." 

Bonner looks back fondly on those days, especially after his 31-disposal performance against Fremantle on Saturday earned him the year's first NAB AFL Rising Star nomination. 

There was method to Port Adelaide's madness with Bonner, whose left foot arrived at Alberton as a weapon – honed, in part, from his soccer days – but other elements of his game needed work.