The City boss is delighted with the capture of the 30-year-old, who scored six goals in 22 international appearances during his reign as England coach.
Vassell has enjoyed a high profile career as a Premier League target man - coming through the ranks at Aston Villa before becoming the subject of a £2million switch to Manchester City - where he again linked up with Eriksson.
However Vassell has been out of action since May after a spell in Turkish football with club side Ankaragucu came to an end and Sven believes it will take some weeks for the striker to gain full match fitness.
Talking ahead of the deal, Eriksson said: 'Darius is not fit to play on Saturday. It will take hopefully two weeks to get him fit.
'He will bring pace and experience, and can score goals. He has been at this level and higher up for many, many years.'
Despite Vassell joining the club at the tail end of his playing career, Eriksson feels he still has a lot to offer the team: 'He is only 30 so he should be able to play for some years. He was in the England squad many times, so he will be good for us.' He added.
It is believed that Vassell - who was selected for the England squad at the 2002 World Cup and 2004 European Championships, will sign a contract keeping him at the Walkers Stadium for two years after completing a medical yesterday.
Meanwhile, Baggies striker Ishmael Miller and Blackburn Rovers hit man Jason Roberts have both been linked with loan moves to City.
The Foxes travel to Elland Road tonight for their Championship clash with Leeds United. The two sides met earlier in the season in the Carling Cup, with Leicester coming out 2-1 winners.