After Bangladesh won the Tests 3-0, new captain Mashrafe Mortaza has had to face questions about a 5-0 win in the one-day series quite regularly. He has always dodged them with the standard "we will take it one game at a time" reply. But on Sunday, he said the team's preparation has given him the confidence to look forward to sealing another whitewash over Zimbabwe.

"I can no longer say that we are taking the matches one by one," Mashrafe said. "It is important to finish well. It is important to continue well, and the players are taking it seriously. We will perform better than the last four games. All the players are confident after going up 4-0 in the last game. Anything can happen in cricket, but we have to be prepared to win and we will give our best."

Bangladesh have batted first, defended well and have won all four games handsomely. The lowest margin had been in the fourth ODI when they won by 21 runs, but the contest had ended by the 40th over of the chase.

There have been phases in the four matches when things didn't go to plan, though. Bangladesh made two great starts with the bat in the second and third matches, but have lost early wickets in the first and fourth. They also had a batting collapse in the second game in Chittagong, but have always fought back hard and ended up in dominant positions.

Mashrafe said that while winning was important, he hoped for a comprehensive display in the fifth ODI and finish the series on a high.

"We have won matches, so we have been consistent in that area," he said. "But performance-wise, we haven't been as consistent. We have to improve in those areas. We are focusing there in training. We cannot collapse again, because it makes life difficult for us.

"It is important for batsmen to bat normally even when they lose a lot of wickets, especially in good conditions. So I think it is always good that we recover from tough situations, when we lost 3-4 early wickets."

Bangladesh have not been shy of changing a winning combination and have so far used 15 players from their squad in an effort to try to test the bench ahead of the World Cup. Soumya Sarkar is the latest to be added to the Bangladesh team for the fifth ODI, and it is likely that he will make his international debut. He is the latest pace bowling allrounder to be picked ahead of Ziaur Rahman and Farhad Reza, seasoned domestic campaigners but with ordinary international records.

Mashrafe said that they were not judging a player by one or two performances - good or bad - but had confidence that Soumya's bowling was good enough for international cricket due to his discipline in line and length.

"It is difficult to judge a player in one or two matches," Mashrafe said. "If it was a 10-match series, it would have been easier but that's not possible. We are not throwing away a player after just one game or judging him on his performance of that one game. But it is true that one match is not enough.

"I don't want to judge anyone. Ziaur Rahman and Farhad Reza are experienced cricketers. Soumya is a very effective bowler, and he can bowl in one spot regularly. Some people think that pace is very important in international cricket, but it is not always true. What he lacks in pace, he makes up in line and length. If he plays tomorrow, I hope he can prove it. I don't want to make anyone feel small, but we had to pick someone among the allrounders."

Mohammad Isam is ESPNcricinfo's Bangladesh correspondent. @isam84