Barbarez refuses to give up on World Cup dream despite Bosnia's defeat to Switzerland
Bosnia held firm until the 74th minute when Switzerland's Johan Manzambi struck three minutes after coming on.
Bosnia defender Tarik Muharemovic's red card six minutes later opened the door for Ruben Vargas, Manzambi again and a stoppage-time Granit Xhaka penalty to complete the rout.
"We have this third game and nothing is lost," Barbarez told reporters. "We have to win it, of course, if we want to get further. This defeat is huge for us, but I don't like whining."
Barbarez felt Bosnia had their best spell before a hydration break midway through the second half, shortly after they created two rare clear openings against a Swiss side that had dominated possession but struggled to break down a packed defence.
"We were the better team (before the hydration break). We had two or three excellent chances which should have ended in goals. We controlled the match and did a lot of pressing," he said.
The breakthrough came after a half-hearted clearance, with Manzambi's right-foot shot helped into the net by goalkeeper Nikola Vasilj.
"This goal should not have happened," Barbarez said. "The goal came from an individual mistake and then we had a red card. Even much more experienced teams get affected by that."
Switzerland exploited the extra space, Vargas firing into the bottom corner before setting up Manzambi's second after 90 minutes.
Bosnia substitute Ermin Mahmic volleyed in a consolation goal early in stoppage time, but Xhaka restored Switzerland's three-goal margin from the spot.
The result left Switzerland on four points before facing Canada in Vancouver, while Bosnia, on one point, meet Qatar in Seattle.
"I told the players they have one hour to cheer up and lift their heads," Barbarez said. "Life goes on. We have another match ahead of us and, trust me, they will be ready."