Grundy made a huge impact late last season, earning plaudits for his ruckwork in the final seven games. 

He led the Magpies into the elimination final, and has earned the mantle of Collingwood's number one ruckman leading into 2014. 

Grundy battled hard against the AFL's premier ruckman, Fremantle's Aaron Sandilands, in the opening round of the season. Despite having his colours lowered, the teenager won respect for his efforts.  

Grundy told Fox Footy's The Club he wanted to re-sign early in the season to remove any distraction during the final year of his first contract. 

"Putting pen to paper was a very big decision. It’s something I didn’t take lightly, it involved all my family, management, and it was something I wanted to get done early," Grundy said. 

"I knew I wanted to stay at Collingwood and play my football here. I didn’t want that dragging out throughout the year."

Grundy was considered a steal at pick No.18 in the 2012 AFL National Draft and made his debut against Greater Western Sydney in round 18. 

Collingwood's football director Rodney Eade said Grundy was the key part of the Magpies' next generation. 

"Since joining Collingwood in 2012, Brodie has tackled every challenge thrown his way with great enthusiasm, and embraced the responsibility which comes with playing a key role at senior level," Eade said. 

"We’ve been delighted by the strides Brodie has made in black and white, and certainly look forward to his continued development in the years to come."