The 29-year-old signed for the Swans in 2012, starring in his debut season in English football as he scored 22 goals in all competitions.
Signed from Rayo Vallecano for just £2million, Michu was capped by Spain as a result of his stunning season, in which Michael Laudrup led the Welsh side to Capital One Cup glory.
Michu struggled with injuries in the following season however, missing out on a chance to star in the Europa League, and eventually being farmed out to Napoli on loan last season.
The Serie A side used him sparingly however, leaving the striker, who has just one year left on his contract at the Liberty Stadium, in transfer limbo.
Boss Garry Monk has moved to alleviate any uncertainty surrounding his future though, insisting he is free to seek a move elsewhere as the club “have kind of moved on”, having added forwards Andre Ayew and Eder already this summer.
“He won’t be with the squad this year,” Monk told the South Wales Evening Post.
“I spoke to him at this point last season, he wanted to go and felt that was right for him and I was happy to support him in that decision.
“I now think we have kind of moved on as a squad. We had a big transition last year.
“I haven’t spoken to Michu – there has been some difficulty with the numbers. I have let Huw (Jenkins, club chairman) deal with his agent and that side of things.
“From what we hear from their side, I think Michu would like to try to move somewhere else.
“That’s the impression I get, although I haven’t had that conversation with him.”
First-team coach James Beattie revealed Swansea are in the market for “one other” major signing this summer, with the likes of Loic Remy having been linked so far.