Two left-handers to lead from the front
Trescothick will lead England in a Test for the first time, while Fleming said he would open the batting.
Two left-handers will lead from the front on Thursday in the opening Test between England and New Zealand at Lord's, the first significant encounter of another crowded English summer.
Somerset opener Marcus Trescothick was named on Wednesday to lead the home side in a Test for the first time after captain Michael Vaughan withdrew with a knee injury sustained in practice on Monday. Middlesex opener Andrew Strauss has been called up as cover for Vaughan.
Trescothick's opposite number Stephen Fleming, the world's most experienced captain, later confirmed he would open the batting for the Kiwis with Mark Richardson in place of Michael Papps, who has experienced problems with the moving ball during the tourists' brief sojourn in England.
Fleming is a regular one-day opener but has gone in first in only one of his 82 Tests, scoring an unbeaten 69 in the second innings against Sri Lanka in Colombo last year while deputising for the injured Richardson.
At a news conference on the eve of the three-Test series, which will be followed by four Tests between England and West Indies before concluding with the Champions Trophy one-day tournament, Fleming said several countries were vying for second place in the world rankings behind Australia.
England demolished the West Indies 3-0 in the Caribbean this year, largely due to outstanding fast bowling by Stephen Harmison, while New Zealand fought a 1-1 draw with South Africa.
"I think there are some teams that are catching Australia up," Fleming said. "I think this series will give a pretty good indication of where we are.
"I think we are seeing an England side that is feeling pretty good and so they should. They have come off a good winter and looking forward to their summer at home."
Trescothick, who has led England in the one-day arena but not yet in a Test match, struggled with his form in the off-season, averaging only 27 in Sri Lanka and 23 in the West Indies.
Before a resurgence of form in the one-day series against West Indies, his footwork was leaden to the point of non-existent, a factor the astute Fleming will have noted.
Choosing his words carefully, Fleming said it would be interesting to see how the captaincy affected Trescothick's batting.
"I think that the pressure will come from within," he said. "You know that Vaughan is going to come back and there's no time to stamp you authority on the team. That is difficult if you have got a different system to employ."
Trescothick said the captaincy had not affected his batting in the past, whether for Somerset or in one-day cricket for England. He scored an unbeaten century against South Africa in a one-day international last year while substituting for Vaughan.
"It's never really bothered me too much," he said. "It may be a little bit different because it's a huge game and it's doing it for your country in a Test match."
Both sides will be relying heavily on their pace attacks with the recent spell of hot weather predicted to come to an end some time over the next few days, in keeping with recent May Tests where spinners have played a peripheral role.
New Zealand have omitted their express bowler Shane Bond to give him more time to recuperate from the stress fractures in his back which threatened to end his career prematurely.
Chris Martin, who took 18 wickets in two matches against South Africa, will be given a chance at the venue where New Zealand began their fightback five years ago to win a four-Test series 2-1 after losing the first Test.
If England's bowling looks stronger on paper, with Harmison backed up by Matthew Hoggard, Simon Jones and possibly James Anderson, New Zealand have the more impressive depth in batting.
Eight of their team have scored Test centuries including number nine Daniel Vettori, whose batting has been more successful than his left-arm bowling recently.
England (from): Marcus Trescothick (captain), Andrew Strauss, Mark Butcher, Graham Thorpe, Nasser Hussain, Paul Collingwood, Andrew Flintoff, Geraint Jones, Ashley Giles, Simon Jones, Matthew Hoggard, James Anderson, Steve Harmison.
New Zealand: Stephen Fleming (captain), Mark Richardson, Nathan Astle, Scott Styris, Craig McMillan, Chris Cairns, Brendon McCullum, Jacob Oram, Daniel Vettori, Daryl Tuffey, Chris Martin.