German daily Bild claims that Inter's director of sport Marco Branca watched Juan twice last week - in the 3-2 away win over Schalke and their impressive 3-0 home victory over Borussia Dortmund which put Bayer well on track for a place in Europe - and is keen to bring the elegant centre-back to Giuseppe Meazza.
The Brazilian international, who arrived in Germany in 2002 from Rio de Janeiro outfit Flamengo, is under contract at the BayArena until 2006.
After a disastrous first season when Leverkusen were almost relegated, he has established himself as one of the Bundesliga's best defenders, starring in a back-three that also contains German international Jens Nowotny and Brazilian World Cup winner Lucio.
With Lucio expected to leave the club over the summer with the likes of Chelsea, Real Madrid and Juventus all chasing his signature, Inter will have to table an irresistible bid for Juan to land the 25-year-old.
Leverkusen will be loath to lose another of their key performers will a return to the European stage on the cards next term.
