"We were as shocked as anyone," Merrett told reporters before training at the Gabba on Wednesday morning.
"We're all pretty shattered for Vossy and just shocked by the announcement yesterday."
Lions officials had insisted a decision on Voss' future would be left until after the season but he was told on Tuesday, with three rounds to play in 2013, that the club would not renew his contract.
Voss and club officials were to front a media conference at noon on Wednesday to discuss the decision.
Asked if the manner of Voss's dumping was unfair on a triple premiership-winning captain of the club, Merrett said: "Yeah. I think in an ideal world you probably would've liked the press conference to be yesterday and Vossy have his say yesterday.
"But we've just got to move on pretty quickly and be united as a group to finish off the year and show what Vossy's done for this group."
On Triple M, Merrett said: "I think it just shows what a ruthless business sport is."
Merrett denied reports the club faced a mass walkout of players if Voss was retained as coach.
'Fab Four' midfield teammate Simon Black said Voss' parting signalled an end of an era for the Lions.
"Yeah, it is," he said. "We were shocked, definitely.
"(But) footy clubs have got to make decisions and it was one of those."
Former Sydney Swans premiership-winning coach and Fitzroy great Paul Roos is being widely touted as favourite to replace Voss.
"All speculation at this stage, isn't it?" said Merrett. "I suppose there is that is that (Lions) connection there.
"I'm sure the board will make the best decision."
