The Brazilian duo impressed in both of Donetsk's Champions League games against Chelsea, with Willian bagging a brace at Stamford Bridge earlier this week.
The 24-year-old has been vocal about his desire to leave the Ukraine in order to secure a move to one of Europe's big leagues, with Tottenham also keen on securing his services.
Now though both Chelsea and Spurs may have to battle Premier League champions Manchester City, who have sent representatives to cast an eye over Willian, as well as his midfield team-mate Fernandinho.
The 27-year-old recently admitted he would like to secure a move to the Premier League, but although both players would like to secure a move away from Donetsk the Ukranian club have previously insisted they are under no obligation to sell up.
Chelsea appear well-stocked in the attacking third after their spending spree in the summer, with Willian's favoured position currently occupied by the likes of Eden Hazard and Oscar. Even the influential Juan Mata has found it hard to secure a central berth this season.
Tottenham meanwhile would welcome the arrival of Willian after the departure of two of their most creative players, Rafael Van der Vaart and Luka Modric, over the summer.
Spurs failed with a move for Willian over the summer, and the Brazilian has revealed he is still in contact with Tottenham manager Andre Villas-Boas.
Citizens boss Roberto Mancini reportedly met with new Sporting Director Txiki Begiristain this week to discuss January transfer targets after a frustrating summer in market.
Manchester City were linked with moves for Daniele de Rossi, Robin van Persie and Eden Hazard but failed to land any of the three, eventually ending the window by bringing in Jack Rodwell, Maicon, Scott Sinclair and Javi Garcia.
Although City looked well stocked in the forward department they have missed the presence of David Silva who is a doubt for their tie against Tottenham tomorrow through injury and hasn't played Premier League football in over a month.
The Spaniard's absence has been felt particularly in the Champions League, and Manchester City bosses may decide they need to add to their creativity by making a move for either or both Donetsk players in the winter window.