Fulham were hoping to add the 28-year-old on loan, but Okaka was reported not to fancy a move down to the Championship and looked set to head to Galatasaray.
However, that move broke down, and now Watford look set to keep hold of Okaka after not signing any strikers this January.
The Whites remain hopeful of signing the striker, but that now looks unlikely, with any ins at Motspur Park looking increasingly doubtful.
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