TuttoMercatoWebstates that Lazio midfielder Sergej Milinkovic-Savic was almost certainly on the scout's watchlist, just months after the Spanish-born Serbian international was linked with a move to Manchester United.
Milinkovic-Savic was identified as a possible replacement for Paul Pogba when the World Cup winner was linked with an Old Trafford exit.
However, the midfielder stayed and United's interest waned.
Now the Stamford Bridge outfit are understood to have been watching the 13-cap Serbia intenational.
Former Rangers defender-turned-pundit Alan Hutton also believes Leicester City may have been running the rule over Hoops midfielder Callum McGregor.
The Scotland international has been linked with a reunion with ex-Celtic boss Brendan Rodgers, who is now at the helm at the King Power Stadium.
Elsewhere, Crystal Palace reportedly sent scouts to Porto v Rangers to watch in-form striker Alfredo Morelos, who scored the Gers' equaliser.