Himmelberg was out of contract at the end of the season but will now continue as a Giant until at least the end of 2019. 

The 21-year-old - pick 16 in the 2015 AFL Draft - made his senior debut in Round 17 last year. 

Himmelberg has since gone on to play 10 AFL games, including six in 2017. 

“This is a really exciting place to be and play football,” Himmelberg said.

“I’ve learnt so much over the first two years of my career and can’t wait to continue that at the Giants over the next few seasons.

“It’s been frustrating having to sit on the sidelines with injury recently, but I’m just keen to be back on the field and put my best foot forward to return to playing in the firsts.”

Giants' General Manager of Football Wayne Campbell added: “Harry’s a great clubman and a really popular member of our group.

“He’s also developing into a quality footballer and one we see as vital to our group for a long time.

“This season he’s shown his versatility and willingness to take on new challenges as we’ve played him in defence, up forward and even in the midfield at times.

“He’s got a great attitude and we’re looking forward to his continued improvement at AFL level.”