Russia have opened up a five-point lead over Portugal following Tuesday's qualifiers, forcing Bento to admit that his side may have to rely on the playoffs to book a brace in Brazil for 2014.
Bento told reporters: "I still believe that we will be in Brazil in 2014.
"We are dissatisfied because we would have given joy to the Portuguese fans but we can only hope that in the next game we get back on the right path.
"The situation depends on us qualifying via the playoff, no longer looking at first place."
Portugal are level with Israel in second place in Group F, five points behind Russia with all three teams four matches into their qualifying campaigns.