Swansea City expect major offers for Michu to arrive later this season.
The 26-year-old's incredible form convinced Swansea to give him a wage rise to £30,000-a-week and extend his contract by a further year to 2016.
But insiders remain convinced the club will be forced to cash in on Michu at the end of the season.
A Swansea source told the Mirror: "The club wanted to reward Michu, but also protect themselves.
"There are still big fears Michu will leave at the end of the season. But at least the club is now guaranteed a big fee and will be in a good negotiating position when bids come in."
Michu has a host of admirers in the Premier League, while rich Russian clubs Zenit and Anzhi Makhachkala are also tracking the Spaniard.