Afghanistan at Zayed Cricket Stadium in Abu Dhabi today.
The two sides switched formats after Bangladesh completed a 3-0 clean sweep in the T20I series.
Miraz said they are keen to keep the momentum going in the ODI series too.
"Wicket looks good and 280 might be a good score here. We played really well in the T20I series and we just want to keep the momentum going," Miraz told the broadcasters after winning the toss.
Bangladesh are playing the first ODI series since their 2-1 defeat to Sri Lanka in July this year.
"This is a very important match, after a long time we are playing an ODI. We have three fast bowlers, two spinners and we have one debutant in Saif. The
way he (Saif) played in Asia Cup and T20 series, I hope he gets going well."
Afghanistan captain Hashmatullah Shahidi said he also would have batted first if they won the toss.
"We wanted to bat, it is a new pitch and I hope the decision they took will benefit us. We have beeen playing domestic tournaments back home and some played the T20 series and let's hope we get good results."
Line Ups:
Bangladesh: Tanzid Hasan Tamim, Najmul Hossain Shanto, Saif Hassan, Mehidy Hasan Miraz(c), Nurul Hasan Sohan, Jaker Ali Anik, Towhid Hridoy, Taskin Ahmed, Hasan Mahmud, Tanvir Islam, Tanzim Hasan Sakib
Afghanistan: Rahmanullah Gurbaz(w), Ibrahim Zadran, Sediqullah Atal, Rahmat
Shah, Hashmatullah Shahidi(c), Azmatullah Omarzai, Mohammad Nabi, Rashid
Khan, Nangeyalia Kharote, AM Ghazanfar and Bashir Ahmad, reports BSS.