The 15-year-old is rated as one of the most promising youngsters at Camp Nou - but Barca are again fearing that he could be tempted away by the lure of the Premier League.
Barca have been hard hit by raids on their youth academy in recent seasons with the likes of Cesc Fabregas and Gerard Pique - to name but two - spirited away by Arsenal and Manchester United respectively.
Now Chelsea, who only last week caused furore in Italy when they agreed a deal for Reggina's 15-year-old Vincenzo Camilleri, are now said to be making moves to land Muniesa.
However, Muniesa's representative Gines Carvajal has insisted nothing has been agreed with Chelsea.
"This is only a rumour because no one from Chelsea has presented a formal offer for the chance of a professional deal," said Carvajal in Sport.
Barca sources insist that they want Muniesa, who turns 16 in late March, to stay and are confident of persuading him to remain in Catalunya.
And Carvajal added: "We are calm, we know that at the end of the season a deal will be done."