Talking about BJ Watling, who hurt his hamstring while warming up on the fifth morning, Stead said the wicketkeeper-batsman was being kept away from the action so that he can be fit for the third Test.
Taylor's 18th Test century, one more than Crowe laid the foundation for New Zealand's 432 for six declared in the first innings of the rain-disrupted Test in Wellington.
Williamson suffered a left shoulder injury while diving in the field during Bangladesh's first innings on Sunday.
Bangladesh have just begun their chase and are now four for one.More news: Trump Tweets About the #FakeMelania Hashtag Conspiracy Theory
Mohammad Mithun was unbeaten on 25 and Soumya Sarkar 12 not out as New Zealand look to force a victory even after the first two days were completely washed out.
It didn't stop him from reaching 50 for the 50th time in test cricket, but once he was dismissed for 74 by spinner Taijul Islam, Williamson headed to a radiology clinic for some precautionary scans, returning in time to see Ross Taylor and Henry Nicholls bring up milestones after tea.
Bangladesh made a disastrous start to their second innings when Tamim, their leading run-scorer, was out for four.
New Zealand humbled Bangladesh by an innings and 12 runs in a rain-affected second Test to claim the three-match series.More news: Nick Jonas just bought Priyanka Chopra the most OUTRAGEOUS gift
Bangladesh, who had needed 221 runs to make New Zealand bat again, were bowled out for 209 as the umpires extended the first session by 15 minutes as a result was likely.
Frustrated by its failure of technique, New Zealand resorted to brute force and called on Neil Wagner to use his contentious bodyline approach to bounce out the Bangladesh batsmen.
Williamson took no further part in the day's play and went for a scan on the shoulder which proved inconclusive and he will have a second scan on Tuesday.
Taylor eventually made them pay by scoring a double hundred. He helped New Zealand negotiate a hard first half-hour Monday when the ball still dominated the bat and went on to reach his half century from 67 balls.More news: 10 things you need to know about Safety Jabrill Peppers
Bangladesh could have made the flawless start to the day, only for Mahmudullah and Shadman Islam to put down Taylor on 20 off Abu Jayed (3-94).