"He will be our leader at the World Cup," Whitaker told Sky Sports after the 16-man squad for a seven-match ODI series in Sri Lanka in November and December was announced on Wednesday.
The left-hand opening batsman faced questions over his form and leadership throughout England's recent home campaign but answered his critics by leading the side to a 3-1 Test series win over India following a defeat by Sri Lanka.
- India's tour of England 2014
However, doubts about his suitability for white-ball cricket persisted following a 3-1 ODI series loss to World champions India.
However, despite a strike-rate of under 80, relatively slow by modern One-day standards, he, as widely forecast, retained his place as both captain and opener in the One-day set-up.
England have never won the World Cup in nearly 40 years' of trying.
The 11th edition takes place in Australia and New Zealand from February 14 to March 29, 2015.
England squad to tour Sri Lanka:
Alastair Cook (Essex, capt), Moeen Ali (Worcestershire), James Anderson (Lancashire), Ian Bell (Warwickshire), Ravi Bopara (Essex), Jos Buttler (Lancashire, wkt), Steven Finn (Middlesex), Harry Gurney (Nottinghamshire), Alex Hales (Nottinghamshire), Chris Jordan (Sussex), Eoin Morgan (Middlesex), Joe Root (Yorkshire), Ben Stokes (Durham), James Taylor (Nottinghamshire), James Tredwell (Kent), Chris Woakes (Warwickshire)
Fixtures
Nov 21: 1st warm-up v Sri Lanka A (Day), Sinhalese Sports Club, Colombo
Nov 23: 2nd warm-up v Sri Lanka A (Day), Tamil Union Oval, Colombo
Nov 26: 1st ODI (Day/Night), Colombo
Nov 29: 2nd ODI (Day), Colombo
Dec 03: 3rd ODI (D/N), Hambantota
Dec 06: 4th ODI (Day), Colombo
Dec 10: 5th ODI (D/N), Pallekelle
Dec 13: 6th ODI (Day), Pallekelle
Dec 16: 7th ODI (D/N), Colombo.
Image: Alastair Cook