Chelsea are reportedly set to up their bid and make a final offer of £15m for Atletico Madrid defender Felipe Luis, according to ESPN.
The Blues have stepped up their interest in the Brazilian full-back after Ashley Cole left the club and completed his free transfer to Italian club AS Roma. Chelsea do not have adequate cover in that position with only the inexperienced Ryan Bertrand being the current option.
Luis has been on the Stamford Bridge club's radar throughout the summer transfer window, and have already had a bid of £12m rejected by the Spanish capital club.
However, Chelsea are going to find it hard to convince the La Liga champions to part with their player, as the club are keen on keeping Diego Simeone's title winning team intact for the forthcoming season.
Atletico are not taking the sudden interest in their top stars too kindly and are willing to play hard-ball with anyone seeking to prise away a player. They have already fended off interest from Barcelona for midfielder Koke and also got Chelsea to match the release-clause for Diego Costa before he could complete his move.
Diego Simeone's side are again looking to squeeze every penny out of Chelsea for their full-back and are not willing to budge until the Blues meet his £19m release-clause.
The 28-year-old defender is said to be keen on making the switch to Stamford Bridge and might go ahead and try to force the move.
Chelsea are also linked with Sporting Lisbon full-back Marcos Rojo and are said to have made a bid in the region of £15m for the full-back.
Jose Mourinho, who has already completed big money moves for Spaniards Costa and Cesc Fabregas, will be keen to get his transfer business done before the start of the club's pre-season plans.