Nicholls, the left-handed middle-order player, has undergone a scan on his right calf after picking up the injury doing running drills in Mount Maunganui ahead of flying out at the weekend with clarity on his availability expected in the next day or so.
“He’s having an MRI scan later today, so we’ll know more after that as to the extent of it,” Stead said. “But he’s got it strapped up and I guess the next 24 to 48 hours will give us an indication of how serious that is.”
Nicholls is a key part of New Zealand’s Test side having made eight centuries in 46 matches with an average of 40.38.
New Zealand face England in three Tests during June with the opening match beginning at Lord’s on June 2. They have two warm-up matches at the end of the May.
There remains a question mark over when the IPL-based Test players – Kane Williamson, Devon Conway, Trent Boult, Tim Southee and Daryl Mitchell – will join the tour depending on the progress of their franchises.
Initially an enlarged 20-player squad has been named to cover for those absences with a reduced 15 names expected to be confirmed before the opening Test.