Chelsea chief Frank Arnesen has made a check on Benfica's players.
The Sun says Arnesen watched Benfica's 4-0 Europa League romp against Vorskla Poltava.
Argentine winger Angel Di Maria, 21, Brazilian defender David Luiz, 22, and Portuguese winger Coentrao, 21, have all caught the eye.
Arnesen said: "We are always looking for good players."