"We have a choice now, whether we be a club that just sits where we are or whether we improve from here," the Cats' captain said.
"We've got to improve. We don't want to be a side that finishes this early in the finals series."
Selwood's message was directed at the club's emerging talent as well as its experienced and decorated players.
"Andrew Mackie, Corey Enright, Steve Johnson, James Kelly need to make that decision (to improve their performances), too," he said.
"We need to push on and get better."
Although Johnson, whose form fluctuated a great deal throughout the season, missed Friday night's loss with a stress reaction in his foot, Mackie, Enright and Kelly all performed well below their best in a defeat that saw the Cats become the first top-four side since West Coast (2007) to bow out of the finals in straight sets.
The indifferent efforts of the veteran trio contributed to Geelong's slow start, which saw it concede seven of the first nine goals of the game.
"Not good enough," was Selwood's summation. "It's a final, and we let them kick 43 points in the first quarter."
Nevertheless, Selwood was proud of the way the Cats fought back and almost pinched a miraculous victory.
"One thing you can't write off is the Geelong spirit," he said.
"We showed that, we just showed it a little bit too late.
"We've got a lot of heart. We play 120 minutes.
"Really proud of the boys. We got ourselves in a position this year to get the double chance, and at the end of the day it's a missed opportunity.
"We’re just disappointed."
The skipper was particularly proud of key forward Tom Hawkins, who made up for his sub-par performance in the previous week's qualifying final against Hawthorn by taking 13 marks and kicking five goals.
Hawkins' haul included three goals in six minutes late in the last quarter, which dragged the Cats back into the contest that looked to be over.
"Awesome, wasn't he?" Selwood said. "He just never gave up. That's what we expect of our leaders.
"And you can give him a hard time all last week and he was always going to come out and do what he did.
"Outstanding person, and I can't speak highly enough of him."
Selwood also praised the work of Josh Caddy (26 disposals and a goal) and Josh Walker (three goals), who were the best of the club's younger brigade.
"We had 10 guys that were 23 or under tonight," he said.
"We could've easily rolled over in that last quarter, but they just fought, they dug in, and I'm really proud of them.
"Disappointing result on the night, disappointing finals series, but they just played it out and played their hearts out.
"We've got the choice now whether we go forward and really develop those guys."
