"Tim [Southee] is normally so reliable but his first over put us on the back foot," Vettori says.
"I had some conversations with him about it. Finding a balance between bowling at off stump early and at the base of the stumps in the death means your action needs to change a bit. He needs to come to terms with the quick turnaround between games and the fact he bowled three overs of perfect yorkers against Sri Lanka. That was an incredible effort."
Coming back into the limited overs side after a hiatus, Vettori says he is trying to help his successor Ross Taylor.
"It is all about timing," Vettori says. "With T20 in particular, there is a great deal going on in the field. You have plans in place but you have to think on your feet and Ross has done that well at this tournament, getting information off other senior guys. You've got to adapt and be as forward thinking as possible."
Vettori says the Indian Premier League has narrowed the gap between the world's top players to a point where there have been few trouncings. Exceptions to the rule have been India beating England by 90 runs as well as Sri Lanka beating the West Indies and Australia beating India by nine wickets.
"Having a more intimate knowledge of players through the IPL has helped. I know our scouting is more intense and specific. Hopefully tapping into such knowledge helps.
"For instance, I can input into how to bowl to Chris Gayle [Vettori played with him at the Royal Bangalore Challengers]. Tim Southee's played with Dwayne Bravo in Chennai and Brendon McCullum has regularly kept to Sunil Narine at [defending IPL champions] the Kolkata Knight Riders. You get some intimate information from that, plus the fact we've come off six weeks playing them at home."
Vettori says despite three consecutive losses the New Zealanders would be deservingly semi-finalists.
"We played well to get a tie against Sri Lanka in a super over which could've gone either way. We didn't play as well against England. To go through we would have to beat the West Indies who are one of the more favoured teams, so I think you could easily put a case forward justifying our qualification."
Vettori says apart from his role as a spin bowler, he will continue to float in the order after batting at four against Pakistan.
"I'm not the biggest hitter but whenever spinners come on my job is to turn the strike over. If there are two spinners bowling, I'll have the pads on."
Andrew Alderson flew to the Twenty20 World Cup in Sri Lanka courtesy of Emirates Airline (www.emirates.com/nz).