The selection panel is not expected to choose a reserve wicketkeeper for the two-month tournament in the Caribbean, but Buchanan Monday still made a case for the New South Wales custodian, without mentioning his name.
Buchanan, who is retiring as Australia's coach after the World Cup, has stressed the importance of having specialist cover for Gilchrist, as well as picking injured all-rounder Andrew Symonds in the 15-man squad.
Gilchrist has a remarkable injury-free record in his 11-season international career, but Buchanan believes there is a risk in relying on him for all the matches in Australia's title defence.
If the team makes the final for a fourth consecutive World Cup they will play 11 games.
Buchanan admitted it was a tough decision as the tournament, including six straight crucial Super Eight matches, allowed few chances for Gilchrist to be rested.
"We've been exceptionally fortunate with Adam in his career that he hasn't sustained any major injury, touch wood," he said Monday.
"But it's such an important tournament that my leaning is to take a second specialist wicketkeeper, but that second specialist wicketkeeper has to offer us more than just wicketkeeping.
"It has to be able to offer us batting potential and probably top-seven material.
"That's my personal leaning and I've expressed that to the selectors."
Haddin, picked for this week's three-match Chappell-Hadlee Trophy series in New Zealand with Gilchrist rested, is the leading run-scorer in the domestic one-day competition with 406 runs at 67 and has batted in all positions in the top seven during his career.
Buchanan defended the timing of all-rounder Shane Watson's return to the Australian side after his pace bowling was shown to be underdone in both finals of the tri-series one-day tournament against England.
The 25-year-old had just 27 overs in state and club cricket but the selectors did not believe the Chappell-Hadlee series would give him enough time to get back into the one-day groove after being a key player as a bowler and opening batsman at last year's Champions Trophy.
"He bowled exceptionally well at the ICC Champions Trophy and in the lead-up to that and batted well so he's on his way back and the quicker we can give him game time, and finals time as that was, the better," Buchanan said.
Buchanan said Watson was a "frontrunner" to open with Matthew Hayden in New Zealand but indicated he would have to bat well further down at the World Cup.
He listed Ricky Ponting, Michael Clarke, Brad Hodge and Michael Hussey as virtual certainties to remain in their positions despite Watson's game suiting a move higher up the order.
"Once we get to the West Indies, all things being equal one would think his primary role would be batting at that lower middle-order position," he said.