The 44-year-old former Yugoslavia midfielder, who took over at Montenegro in September and sealed their play-off berth with a 2-2 home draw against England, believed his team could turn the tie on its head with a similar gritty performance.
"We were able to erase a 2-0 deficit against England in just 45 minutes so I am sure we can do it over 90 minutes against the Czechs, who are not in the same quality bracket with the English," Brnovic told Montenegrin media.
"I am confident we can score two or three goals and my only worry is that we might concede one while taking risks and leaving gaps at the back.
"Some might call me crazy but I am optimistic that the Czechs are staring at a 3-0 defeat in the return leg because I know my players will leave it all on the pitch, roared on by our passionate fans in the cauldron of Podgorica stadium," he said.
Montenegro, a tiny Adriatic republic with a population of just 650,000, will have to dig deep into their slim resources if they are to end the Czech Republic's proud record of qualifying for every European Championships since they split from Slovakia in 1993.
Montenegro's limited options played a big part in their first-leg defeat, when Brnovic made a substitution on the hour which backfired and put the visitors on the back foot for the rest of the match.
"Dejan Damjanovic was one of our best players until he made way for Vladimir Bozovic, but he was often left outnumbered on the left flank and the idea was to add some substance on that side of the pitch," Brnovic said.
"It didn't work and I must take sole responsibility for the defeat, although we were unlucky not to score when it was 0-0 and especially so to concede the second goal in injury-time."
Czech hopes of advancing to next year's tournament in Poland and Ukraine will also rest on the good form of versatile Arsenal midfielder Tomas Rosicky, who pulled the strings in midfield and gave his markers a roasting.
"We are in a very good situation now and it would be a real pity to not capitalise on this result and not qualify," said Czech coach Michal Bilek.
