Former New Zealand pace bowler Simon Doull wants drastic changes in the New Zealand T20 set-up, including the replacement of the captain and coach. Doull said the current T20 squad had too many Test players, and stated that captain Kane Williamson shouldn't be in the side unless he opens.

"I don't think we are getting the selections right. I've had some concerns for a while," Doull told Radio Sport. "If Kane Williamson doesn't open in T20, he shouldn't be playing. His record opening is very good - at three and four, it's not that great. But he shouldn't be in the T20 side, there's a lot who shouldn't be in the T20 side."

Williamson has scores of 8, 9 and 0 from his last three T20 internationals and the last knock of 8 against Australia came from 21 balls while batting at No. 3 in Sydney last week. In his last 11 T20I innings over the last 12 months, Williamson crossed 30 only once and had a strike rate of 100.54 and average of 18.60.

Doull was not critical of the team's performances under Hesson but was wary of how the current cricket calendar was hardly giving the coach any time off. He also suggested that finding a younger replacement for Hesson, who is 43, only for the T20 side could help bring about an overall change in approach in the shortest format. Since the beginning of last year, New Zealand are fifth among the current Test-playing nations, with a win-loss ratio of 1.17 after Pakistan, India, South Africa and West Indies.

"He's a great coach who has done an amazing job, and has really grown into the job," Doull said. "But he gets very little time off, only a small amount of time with his family. Give him T20 completely off, get a new coach, new ideas, a new bunch of players.

"[The coach] probably needs to have played the [T20] game to understand it a bit better. The Northern Knights [winners of this season's Super Smash] had Gareth Hopkins solely as their T20 coach and he had played until recently. The rest of the coaches around the country are a bit older, out of touch with T20."

Doull, who has been a leading commentator for several years now, called for injecting more dynamism in the existing structure for the shortest format. He said senior batsman and limited-overs specialist Martin Guptill would "relish the captaincy and responsibility" if he was asked to take over the reins from Wiiliamson. In addition, he suggested that Colin de Grandhomme be promoted up the order and that Anton Devcich, Mark Chapman and Tim Seifert be given an opportunity ahead of Ross Taylor and Tim Southee.

"I would like to see Colin de Grandhomme batting higher but it is the selections, not the batting order [which is the problem]. We want dynamic players and should be giving them an opportunity at T20 level."

At the SCG, in the opening T20 of the Trans-Tasman Trophy, New Zealand had managed only 117 for 9, after a 24-ball 38 from de Grandhomme relatively revived the team from 60 for 5.