Chelsea reportedly had scouts in attendance for Tuesday's Champions League clash between Lyon and RB Leipzig with Moussa Dembele and Timo Werner watched by the London giants.
The Blues, having had their FIFA-imposed transfer suspension lifted, are expected to bring a new centre-forward to the club when the January transfer window opens for business.
According to the Daily Mail, both Dembele and Werner are under consideration by Chelsea, with scouts from the Premier League club watching the pair in action during the 2-2 draw.
Werner netted from the penalty spot in the European tie to make it 20 goals in 22 appearances for Leipzig this season. Dembele could not get his name on the scoresheet for the home side, although the Frenchman has still managed 10 goals in all competitions this term.
Tammy Abraham has been Chelsea's first choice in the centre-forward spot this season - scoring 13 times in all competitions - but Olivier Giroud has struggled for football and is expected to move on at the start of 2020.
Frank Lampard's side are also believed to be interested in Crystal Palace's Wilfried Zaha, Borussia Dortmund's Jadon Sancho, Bournemouth's Nathan Ake and Leicester City's Ben Chilwell.