The release clause of RB Leipzig forward Timo Werner is reportedly due to expire on July 15.
While Chelsea have made a big push to sign the Germany international in a £54m deal, their efforts have appeared to be in line with the belief that the set fee was only available until June 15.
However, according to Bild, any interested clubs, in theory, have until a month later to make an official approach for the 24-year-old.
Although it is reiterated that Chelsea remain the favourites to sign Werner, it leaves the door open for the likes of Manchester United to make a late swoop.
Earlier in June, it was claimed that United had offered a contract to the versatile attacker before he indicated to Chelsea that he was ready to move to Stamford Bridge.
The Blues may have to wait until the end of the month to hold a medical with the player.