Leandro, who is a star of the Argentine Under-21 side, is in Rome to seal a five-year deal with last season's Scudetto winners - and could forge a key partnership alongside compatriot Walter Samuel.
Roma started the season with a somewhat disappointing 1-1 draw against Verona after Massimo Oddo cancelled out an opener from Samuel, and Capello has been open in his desire to bring a top-class defender to the club.
The former Milan boss will have been upset to see neighbours Lazio pull off a major coup in signing Manchester United's stalwart centre back Jaap Stam, but the arrival of promising Leandro - who has already grabbed two world titles for the Under-20 and Under-21 sides - will temper his frustration.
