Before IPL 2020 began, Shane Bond, the Mumbai Indians bowling coach, felt Trent Boult hadn't fully realised his potential as a T20 bowler. Now, after a season in which Boult took 25 wickets - including a record-equalling 16 in the powerplay overs - to help the Mumbai Indians win their fifth IPL title, Bond is thrilled with the left-arm quick's growth.

"Getting the chance to work with Boulty again was exciting," Bond said in a media interaction hosted by NZC. "I was always a believer that there was room for improvement in his T20 game, and coming into our team, we could eke that out of him, and he was massive for us. He was a huge part of why we won, so hopefully we won't have a big option and we may lose him - love to have another chance to work with him another year and keep that team of ours together because it's pretty good."

Bond feels that Boult has become a certainty for New Zealand at the next T20 World Cup, scheduled to be held in India in October-November 2021. He reckoned New Zealand's upcoming T20I series against West Indies - from which Boult has been left out to rest him ahead of the Tests - would be an opportunity for head coach Gary Stead to look at newer faces, such as Kyle Jamieson, and see which fast bowlers could dovetail with Boult come World Cup time.

"I think [Boult is] a lockdown, a lay down misere in terms of the T20 World Cup squad, and I think you've got to effectively use the games coming up to find out who may be the support acts for him in and around that T20 World Cup team.

"I think it's important [Boult gets a break. He's got a couple of young kids. To fly out from here and go straight into games and not have a chance to catch up with his family would have been a massive mistake" Shane Bond

"There's no problems from my perspective in giving those other guys, guys like Jamieson, another opportunity to see what they've got, so that Gary's really clear when it comes to picking his 15-16 for the next T20 World Cup, so he's got all his bases covered."

Bond is presently in Lincoln, as one of two guest coaches - Brendon McCullum is the other - in the managed isolation facility where six New Zealand players returning from the IPL are training ahead of the series against West Indies. He feels New Zealand made the right call to rest Boult from the T20Is and give him an opportunity to spend some time with his family before returning to life in a bio-secure bubble.

Boult is part of the IPL group in Lincoln until his 14-day quarantine period ends, and he is using that time to bowl longer spells and get into Test-match rhythm after 15 games in the IPL.

"I think it's important [Boult gets a break]," Bond said. "He's got a couple of young kids. To fly out from here and go straight into games and not have a chance to catch up with his family would have been a massive mistake.

"I suppose part of him being here is to get a little bit more volume, in terms of his overs, under his belt. It's always a challenge when you're in the IPL - it's stinking hot, you don't train as much, and obviously you're playing a game that's four overs. So it gives him a little bit of time to get some volume here and in the week, two weeks before the Test matches start against the West Indies.

"I think for his own sanity, he just would need to get home and spend a little bit of time with his family before he has another busy summer, so it's a good decision."

Bond has worked with Boult in his stint as New Zealand's bowling coach from 2012 to 2015. From then to now, Bond is delighted with how far Boult has come in becoming one of the world's best fast bowlers.

"With guys like [Jasprit] Bumrah, those sort of players who are experienced and gun bowlers, what you sense is that inner confidence within themselves and they know what they're doing, and I think that's the thing [with Boult as well]," Bond said. "You go back to when I started from '12 to now 2020, eight years is a long time, he's played a lot of cricket, got a lot of wickets. So all the little things you notice the difference.

"He's aware of his mental processes and where he wants to improve. Technically he's very aware of the things that work and don't work, and then you as a coach, you're trying to find the subtleties of how to make his game better. For me, that was a lot around tactically and around his T20 game.

"The one thing about great bowlers or bowlers who've had success is sometimes it's harder to move them, because they've found a mode of success. So the good thing for me, having been where I am now for a period of time and worked with Trent is, I don't have to worry about building the relationship, we already always had a strong relationship, so you have that trust and so you can work together to try and find improvement, because even as good as Trent is - and he's unbelievable - there are always ways to improve and get better.

"We had a hell of a lot of fun, it's always nice to see someone you like come in and have success, and to share the spoils at the back end was cool."