The 52-year-old must announce his final 23-man group by the June 2 deadline.
No fewer than three Chelsea players - John Obi Mikel, Victor Moses (on loan at Liverpool) and Kenneth Omeruo (on loan at Middlesbrough) - have been included in the preliminary party.
In-form Stoke City striker Peter Odemwingie also finds a place in the 30-man party after making peace with Keshi, and so does 33-year-old defender Joseph Yobo, who joined Norwich City on loan from Fenerbahce in January.
Celtic centre-back Efe Ambrose, who has been in impressive form in the Scottish Premiership, is part of the provisional squad too.
However, Hull City forward Sone Aluko has not been called up, while former Newcastle United striker Obafemi Martins, now with MLS club Seattle Sounders, has also been omitted.
Nigeria have been drawn against Argentina, Bosnia & Herzegovina and Iran in Group F of the World Cup.
The 2013 Africa Cup of Nations winners will start their campaign in Brazil against Iran in Curitiba on June 16 and then five days later will face Bosnia.
The African giants' final group game will be against South American powerhouse Argentina in Porto Alegre on June 25.
Nigeria's provisional World Cup squad:
Goalkeepers: Vincent Enyeama (Lille), Austin Ejide (Hapoel Be'er Sheva), Daniel Akpeyi (Heartland), Chigozie Agbim (Gombe United).
Defenders: Elderson Echiejile (Monaco), Efe Ambrose (Celtic), Godfrey Oboabona (Rizespor), Azubuike Egwuekwe (Warri Wolves), Kenneth Omeruo (Middlesbrough), Juwon Oshaniwa (Ashdod FC), Joseph Yobo (Norwich City), Kunle Odunlami (Sunshine Stars).
Midfielders: John Mikel Obi (Chelsea), Ramon Azeez (Almeria), Ogenyi Onazi (Lazio), Joel Obi (Parma), Nnamdi Oduamadi (Varese), Ejike Uzoenyi (Enugu Rangers), Nosa Igiebor (Real Betis), Sunday Mba (CA Bastia), Reuben Gabriel (Waasland-Beveren), Michael Babatunde (Volyn Lutsk).
Forwards: Ahmed Musa (CSKA Moscow), Shola Ameobi (Newcastle United), Emmanuel Emenike (Fenerbahce), Victor Obinna (Chievo), Peter Odemwingie (Stoke), Michael Uchebo (Cercle Brugge), Victor Moses (Liverpool), Uche Nwofor (Heerenveen).