"If we are not motivated now to reach the finals of an international tournament we would hardly ever be motivated for anything else," Bento told journalists.
"We head into this play-off with maximum confidence. This time we have a wider range of choices to pick the squad from with three of our regulars returning from injury," he added.
As well as the return of Coentrao and Pepe, Bento also has Besiktas striker Almeida back after injury forced him out of the last two qualifiers against Iceland and Denmark.
The return of the two defenders may prove crucial following Portugal's wobbly performances in defence in their last two matches, in which they conceded five goals.
Last month, Portugal beat Iceland 5-3 at home but their 2-1 defeat in Denmark in their last qualifier meant they finished second in Group H behind the Danes who qualified for the finals automatically.
"We are confident. What happened in Denmark is in the past. We have to look up and face reality which now comprises the Bosnia matches," Cristiano Ronaldo told Antena 1 radio.
"Portugal has a great team and great players. We have to show that we are favourites and assume it. I am confident that Portugal will be in the Euros," said Ronaldo, who is set to receive the Golden Boot award later today.
The world's most expensive player earned the prize for being the top scorer in league matches in Europe, notching a superb 40 goals for Real Madrid in Spain's La Liga.
Bosnia coach Safet Susic has said he expects the playoff to be extremely tight as his side seeks to avenge their 2-0 aggregate playoff defeat to Portugal back in 2009 that saw them out of the World Cup in South Africa.
Forwards: Cristiano Ronaldo (Real Madrid), Danny (Zenit St. Petersburg), Helder Postiga (Real Zaragoza), Nani (Manchester United), Ricardo Quaresma(Besiktas), Nuno Gomes (Braga), Hugo Almeida (Besiktas).