Chelsea have failed with two deadline-day bids for Paris Saint-Germain centre-back Marquinhos, according to Sky sources.
It is understood the Blues have offered two separate sums between the £25.7m and £40.4m-mark for the Brazil international.
Jose Mourinho has been on the hunt for a new centre-half after missing out on John Stones, for whom they bid three times to try and secure a sale from Everton, only for all of them to be rejected.
But they have also been keen to add the experience of Marquinhos, who has played in the Champions League and the World Cup for Brazil despite being only 21 years of age.
Marquinhos signed for PSG from Roma in 2013 and has made almost 50 appearances for the French Ligue 1 club.