Chelsea head coach Thomas Tuchel has acknowledged that Timo Werner and Romelu Lukaku will miss the next two matches through injury.
Both players were withdrawn during the first half against Malmo on Wednesday night, Lukaku sustaining an ankle injury and Werner suffering a hamstring problem.
While there has been speculation regarding the potential recovery time for both players, Tuchel has refused to put a specific date on their time on the sidelines.
Speaking to reporters at a press conference, the German said: "No big news for Timo and Romelu. All I can say is that they are out for tomorrow and out for the Southampton game.
"From there, we will see what is next. It does not make any sense we go into speculations for how long this is going to be. Things can be shorter than expected and longer than expected.
"The one thing I can say is that they are both undergoing treatment and both feeling positive."
Chelsea face a period of five matches in 15 days before the next international break, starting with their Premier League fixture against Norwich City on Saturday.