Moyes will make the move if he fail in his bid to bring Henrik Larsson to Goodison Park.
The Everton boss needs to strengthen his attack as Yakubu is ruled out for the season with a raptures Achilles and Louis Saha is struggling with a hamstring problem.
Moyes believes a £3million bid can persuade Portsmouth to sell their striker.
Nugent joined Pompey from Preston for £6million, but have made just one start for the club this season.