Bulgaria, who have failed to reach a major tournament since Euro 2004, host leaders France on Saturday, knowing only a win will keep their chances of playing at the finals in Russia next summer alive.
"There are still games to be played in the group and a turnaround is possible," said Spartak Moscow striker Popov, who will miss the France game due to suspension.
France top the standings with 17 points from eight matches, followed by Sweden on 16. Netherlands are third with 13 points while Bulgaria are fourth on 12.
"We'll go out and try to take maximum points in these two matches (Bulgaria visit Luxembourg in their final game on Tuesday), so they really shouldn't write us off," Popov said. "We're very strong at home."
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The eight best runners-up from the qualifying groups in Europe will play home-and-away over two legs with the winners going through to Russia.
Bulgarian media, fans and former international players recalled the Balkan country's famous victory against France at the Parc des Princes in 1993 to help inspire the players ahead of the clash at Vasil Levski stadium.
A dramatic last-minute goal by Emil Kostadinov gave Bulgaria a 2-1 win over France to clinch a place at the 1994 World Cup finals in the United States, breaking French hearts as Gerard Houllier's team were eliminated.
Bulgaria then went on to reach the semi-finals after beating Germany in the last eight.
Local media even suggested that the presence of Kostadinov's namesake - Maccabi Haifa midfielder Georgi Kostadinov, in Bulgarian squad could be a good omen for the team.
(Reporting by Angel Krasimirov; editing by Sudipto Ganguly)
