Ze, 26 was top goalscorer in the Portugese League with 17 goals. He made a summer move to Levante UD from OS Belenenses but the move has not worked out.
Ze told the Spanish press: "If I do not play here at Levante then it would be normal for me to leave because I no not want my chance of playing blocked each Sunday.
"English football is a very attractive option and African players seem to adapt well to the Premier League.
"I await a definitive decision on my future over the next week."
It is expected that Sheffield United could pay £2,000,000 for the forward. He also lists Ian Harte and Laurent Robert who were formerly with Leeds United and Newcastle as his team mates.