Chelsea are reportedly monitoring Mehdi Taremi after sending scouts to watch Porto's 4-1 win over Braga.
The Blues made an approach for the Iran international in the final days of the summer transfer window, but Porto were reluctant to sell the striker due to his importance to the club.
Instead, Chelsea opted to sign Pierre-Emerick Aubameyang, but they are still believed to be interested in acquiring Taremi, who has two years left on his Porto contract.
According to football.london, Chelsea sent scouts to watch the 30-year-old play the duration of Friday's commanding victory over Braga, where he registered an assist.
Chelsea were one of 15 clubs that had representatives at the game to take a closer look at several players, including Tottenham Hotspur who were reportedly focusing on David Carmo.
Although he failed to find the net on Friday, Taremi has scored seven goals and provided four assists in 10 appearances this season.