The 22-year-old joined Vitesse at the start of this season but has struggled to force his way into the first-team at the Eredivisie side.
He has made just two senior appearances so far, both as a substitute, and was unlikely to have many more chances in the second half of the season.
As such, Vitesse have agreed to cancel the loan deal and allow Junior to move to Norway, with the new season set to start in March.
He will remain there until July before re-joining the Everton squad ahead of the 2014/15 season, though it remains to be seen whether he will ever force his way into the first-team set up at Goodison.
The former Portugal Under-21 international signed for the club on a free transfer in the summer of 2012 but has made just one senior appearance so far, in the disastrous League Cup defeat to Leeds the following September.