The Spanish striker, who joined the South Wales side in 2012, struggled in the 2013-14 Premier League season with knee and ankle injuries, failing to match his 22-goal debut campaign in the top flight.
However, the manager told Wales Online: "He has definitely not been put up for sale by anyone at this club, me, the chairman or anyone.
"Our only discussion about Michu is getting him back to fitness and making sure he's on the pitch for Swansea and scoring goals.
"He's a goalscorer, our top scorer two seasons ago, so that's not something you dismiss very lightly. We want him here at the club."
The 28-year-old scored six goals for Swansea last season.