BCB president Nazmul Hassan said the allrounder informed the board “unofficially”, and would need to do so “officially”

“He hasn’t informed us officially. He told us unofficially,” Hassan said. “We told him to inform us officially. He has to give a reason. Shakib contributes with either bat or ball. He strengthens the team combination. There’s no substitute for Shakib.”

The selectors have picked an 18-member squad for New Zealand that includes six fast bowlers, three spinners and three openers.

Among the fast bowlers, Taskin Ahmed is the likely attack leader although he still has to recover from the finger injury sustained during the T20I series against Pakistan. The others are Khaled Ahmed and Ebadot Hossain, who are currently playing the second Test in Dhaka, as well as Abu Jayed, Shohidul Islam and Shoriful, the only left-armer.

The New Zealand series will count towards the 2021-23 World Test Championship. The first Test is set to be played in Mount Maunganui from January 1 to 5, and the second in Christchurch from January 9 to 13.

Bangladesh squad for New Zealand Test series: Mominul Haque (capt), Shadman Islam, Najmul Hossain Shanto, Mushfiqur Rahim, Shakib Al Hasan, Liton Das, Nurul Hasan, Yasir Ali, Mehidy Hasan Miraz, Taijul Islam, Taskin Ahmed, Abu Jayed, Ebadot Hossain, Shoriful Islam, Khaled Ahmed, Shohidul Islam, Mahmudul Hasan Joy, Mohammad Naim