According to Malaysia newspaper The Malay Mail, talks are on the way to bring two of Europe's biggest football clubs to the capital in June.
It would Barcelona's first visit to Malaysia, with unconfirmed reports claiming the Spanish giants could also drop by Indonesia and India.
But according to The Malay Mail, insiders revealed it remains premature to speak about the possibility of Lionel Messi and company playing in KL.
"Discussions are still ongoing. At the moment, MU looks the better prospect but even that is yet unconfirmed," a source was quoted as saying.
As for United, their last visit to the Malaysia capital was back in 2009.
KL hosted Liverpool, Chelsea and Arsenal at the Bukit Jalil Stadium last year.