The English centre-back spent last season on loan at Roma and impressed, becoming a firm favourite at the Italian side.
Roma have been attempting to bring Smalling back from Manchester United on a permanent basis, but reaching an agreement with the Red Devils has proven to be tough.
The deal is nearly over the line though and, according to Inside Futbol sources, intermediaries working on the deal are still in Rome.
There are still several details which must be finalised before Smalling can join Roma once again.
The centre-back wants to move back to the Stadio Olimpico and looks set to get his wish.
Smalling, 30, clocked up 30 appearances in Serie A for Roma last season and even chipped in with goals against Udinese, Brescia and Torino.
His final league game for the Giallorossi was a 3-1 win away at champions Juventus.