Barrett said there was an immediate hush among the playing group when Lyon broke down at training in the captain's run before he was forced to withdraw from playing Melbourne.
"(The players) were pretty devastated, to be honest. The session did stop for a while because we all know what the outcome was going to be when he did do it at training," he said.
"Everyone feels really sorry for 'Killer'. We wanted to send him out this weekend at Brookie. But we've just got to get on with it now and make sure Killer still gets the send off he deserves."
A typically humble Lyon accepted that his career is now over.
"It's not the best. I would've loved to be out there with the boys and had one last game at Brookie, it would've been great," he said.
"I've had a lot of games over the years at that ground and played with some great players. I'm privileged to be a part of the club."
The injury all but brings an end to a glittering 17-year career that includes two premierships, four grand finals, eight Kangaroos jumpers and 10 State of Origin appearances for NSW.
He is a four-time Dally M centre of the year, two-time Dally M captain of the year, and the winner of Super League's prestigious Man of Steel award in 2005.
Halfback Daly Cherry-Evans predicted there would be some learning curves without Lyon's trademark calmness on and off the playing field next year.
"Playing alongside him, it's definitely a satisfying feeling when your captain is the most level-headed player out on the field. It's definitely helpful as a young half coming through," he said.
"It is going to be different and I dare say at times it will be difficult not understanding what to do without Jamie Lyon there. But I feel as though we do have some great leaders coming through, this next wave of Manly players."
- AAP