"Before [Daniel] Vettori comes back, Sodhi must stay in and around the team environment and be involved even when he's not playing because that is a critical investment that New Zealand Cricket needs to keep making."
Vettori will return after the West Indies series, Cairns believes, despite media speculation the ND veteran is signalling his retirement from red-ball cricket.
Finding "top-line" support for Sodhi is imperative, he reckons.
"Graeme Swann has Mustaq Ahmed to sit with at the end of the day to discuss how, you know, things are working.
"Nathan Lyon has Shane Warne available in the commentary box to have a chat with."
Sodhi, with Vettori around, will be very helpful but they must also invest in people on the side with the talent that is coming through.
While former Pakistan international Mushtaq was involved with the Black Caps stable during the recent subcontinent tours, he feels there's still a need for a specialist.
"One of the best legspin coaches around is Abdul Kadir so it's whether New Zealand Cricket is in the mindset to be able to look to have that quality around."
Vettori is in "our own backyard but Dan's got to focus on his own career. Once Dan's finished then it's a different role".
"At the moment he can help but he's also got to make sure his game's right so you can't burden him with too much."
Spinners, Cairns believes, will only come into the equation when New Zealand are capable of posting totals in the vicinity of 400 to 500-plus runs.
"If you don't have the runs to play with then inexperienced spinners can become a liability."
Just as Doull had expressed concern with Kane Williamson's fitness, Cairns also emphasises the camp should take a stance of "either he's fit or not fit".
The ND batsman was ruled out yesterday.
Cairns does not want to be drawn into the captaincy debate with Brendon McCullum's back ailment.
"For me it's about McCullum's captain so let's not talk about it until it happens."
