The batsmen should step up and give the bowler some runs to defend, Tamim said.
The Tigers had a week-long preparation camp in Queenstown ahead of the series. They also had a practice camp in Dunedin.
"We practised a lot during the quarantine period and also did it in Queenstown before coming to Dunedin. So there should not be any excuse for the preparation," Tamim said on Saturday.
Also read: New Zealand crush Bangladesh in 1st ODI
Bangladesh were sent to bat first after losing the toss and failed to show any plan against the hosts' pace-bowling attack. Trent Boult bagged four wickets while the other pacers also did well.
The visitors got bundled up for 131 – their lowest ODI total against the Kiwis after 2007.
Tamim made a good start – hitting a six off Boult. But Bangladesh failed to carry on as Tamim and Soumya Sarkar were removed in the same over off Boult.
"We had four-five soft dismissals which pushed us to the backfoot and could not recover from that," Tamim said. "Had we posted 250-260 runs on the board, the result could have been different."
Also read: Tamim to skip New Zealand T20Is for personal reasons
New Zealand had to play this game without the service of their regular captain Kane Williamson and veteran batsman Ross Taylor.
It was the first time in eleven years that both Williamson and Taylor were out of the Kiwi eleven in ODIs.
New Zealand fielded three newcomers in the game. But the Tigers failed to capitalise on that and handed them a big win.