Manchester United are keeping tabs on Lazio's Felipe Anderson, Southampton's Sadio Mane, Leicester's Riyad Mahrez and Ajax's Anwar El Ghazi as Louis Van Gaal looks to add a winger to his squad in January.
The Daily Mail is reporting chief scout Jim Lawlor was present at Lazio's Europa League clash with Rosenberg, but Anderson didn't feature in the game.
Van Gaal indicated this week that he's looking to add some pace on the wings to his team. He said: "I have said already in my first year many times we need speed and creativity on the wings.
"You have seen that now we play with Jesse Lingard and he is not the most speedy winger in the world and Mata is also not the most speedy winger in the world.
"So we must first finish that problem and then we can see how we have to play and how we are in balance with playing with speedy wingers."