Bangladesh were bundled out of the tournament after four straight losses in the Super 10 group stage -- including a crushing 75-run defeat to New Zealand on Saturday.
But Mortaza said they were hobbled by the International Cricket Council's (ICC) decision to bar key pacemen Taskin Ahmed and left-arm spinner Arafat Sunny early in the group stages.
Bangladesh, whose side finished runners-up to India in the Asia Cup just before the World T20, made a failed frantic appeal to the ICC to have Taskin's suspension overturned.
"In the last eight matches, Taskin's economy rate was the best in the world. So it was always difficult to lose him," Mortaza said at Dhaka airport after returning home.
"The way he was bowling, we had our plan set around him. We had to change the entire game plan. Before the Australia game when he was banned we could not hold our emotions due to this shock.
"We accepted that Sunny's action has problems. Even Sunny himself accepted it. But Taskin's ban was a complete shock for us," he said.
Bangladesh qualified for the group stages after commanding wins over the Netherlands and Oman, and Mortaza said the tournament had been a good learning experience.
"From now on, whoever we face, if we don't keep making small mistakes, it will not be easy to beat us. This is what I believe. We could not do this in Twenty20 in the past."
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ