Niclas flew from Merseyside late on Thursday night to complete the deal - and allow him the opportunity to meet, and train with, his new team mates on Friday.
Although, as caretaker manager, Trevor Brooking was reluctant to bring in too many players, he feels that 31 year old Niclas' pedigree makes his signing an obvious decision.
Niclas has played 68 times for Sweden, scoring seven times, and has played over a half century of matches for Everton since joining from Sheffield Wednesday in 2000 for £2m.
"You can try the untried youngster but you are really looking for someone who has played in the Premiership and who has played at different levels," says Trevor.
"I know Niclas has played at the top level and is capable of doing it, and it was just about making sure about current match fitness, attitude and everything else.
"If he plays as we know he can perhaps it will be extended a bit longer.
"We certainly needed another midfielder and, ideally, wide right because that is what you need to play a 4-4-2, which you will at times in this league.
"There is a flurry of games coming up and from my own point of view I don't want to be too active in the transfer area - because if we do resolve anything in the next week, two, three, or whatever I wouldn't have wanted to bring someone somebody else with their own ideas might not be keen on.
"So it is a case of trying to get a balance between trying to deal with the next three weeks when we have a lot of games, and then not clogging up the squad because we want to give a bit of flexibility if there is a chance of someone coming in in the next few weeks."
Niclas started his career at his home town club Halmstads, where he spent six years, before moving to IFK Gothenburg for two years before going to Hillsborough in 1997 for £750,000.
He has initially signed for a month.