The Nerazzurri are looking to provide competition for full-back Sime Vrsaljko and both the former Torino defender -- who was recently being linked with a move to Inter's Serie A rivals Juventus -- and the former Sporting Lisbon defender are under observation.
Initial enquiries have already been made about both targets, a source close to the Serie A club have told ESPN FC..
Darmian, 29, has been capped 29 times by his country and earned a move to Old Trafford with his performances for Torino, after starting out his career at Inter's city rivals AC Milan. He has made a total of 115 Serie A appearances and scored two goals.
Portugal international Soares, 27, has played 22 times for Southampton this season and is also being considered by Inter, who are bidding to return to the Champions League next season after being eliminated in the group stage this term, following a draw in their final group game 1-1 with PSV Eindhoven -- a result which saw them finish behind Tottenham on head-to-head.
They face Rapid Vienna in the round of 32 of the Europa League and are at home to Lazio in the quarterfinals of the Coppa Italia.
The gap to Serie A leaders leaders Juventus is 16 points, meaning their objective in Serie A is to finish inside the top four and a new full-back is being sought by coach Luciano Spalletti to strengthen his squad for a busy four months.