Brown ruptured his anterior cruciate ligament at training on Monday and will undergo a traditional knee reconstruction.
The 22-year-old key defender spent most of last season playing second fiddle to Simon Prestigiacomo but got his chance in round 18 and never looked back, nullifying St Kilda star Nick Riewoldt in both grand finals.
While Goldsack said everyone at the club was devastated by the news of Brown's injury, it would open up the door for other players, like Keeffe to come through the ranks.
"It's definitely not a good thing for Browny but it does open up opportunities for other people," Goldsack told afl.com.au.
"We've got Lachie Keeffe coming through the ranks as well so hopefully he can kinda fill in when he needs to, and hopefully he can play every game, I'm not ruling it out."
At 204cm tall, Keeffe was rookie listed as a ruckman in the 2009 Rookie Draft and has been elevated to Collingwood's senior list this year.
With Josh Fraser and Cameron Wood sharing duties in the ruck last season in the Pies' VFL side, Keeffe was moved to the backline to develop as a key defender.
The move proved to be a success, one that could earn him a senior debut this season according to Goldsack.
The Pies should have no trouble filling the void left by Brown with new recruit Chris Tarrant adding to the club's depth in defense, as well as Goldsack himself vying for a permanent spot down back.
"It definitely is [handy to have Tarrant back]. It's good to have that depth in the team," Goldsack told afl.com.au.
"But then again, hopefully I can get a game too."
Teammate Harry O'Brien spoke to Brown on Tuesday and said he would bounce back stronger than ever.
"He's doing great but it's going to be a really tough time for him," O'Brien said.
"Given his age and the character he is, I've got no doubt he will learn some valuable lessons from the experience and comeback a stronger person."
Goldsack echoed his teammate's sentiments and said Brown's positive personality would help him through his lengthy rehabilitation.
"He's always up and about," Goldsack said.
"It won't break his spirit but it might dint it for a little bit. He'll do all he has to. He's very professional in that way.
"So he’ll do all the recovery he needs to do and be back probably quicker than anyone else would."
Tyson Goldsack is a $216,900 defender in the Toyota AFL Dream Team competition.
Harry O'Brien is a $260,300 defender in the Toyota AFL Dream Team competition.
Lachlan Keeffe is a $92,500 defender in the Toyota AFL Dream Team competition.
