The striker is expected to be out of action for Lazio for two weeks having returned to Germany for specialist treatment on his right foot.
The Germany international returned to his homeland to consult a specialist in Munich after suffering a recurrence of inflammation around the metatarsal bones in his right foot, with the decision subsequently taken to operate.
Lazio is confident of having the ex-Bayern Munich forward available after the international break, with the away fixture against Atalanta on Oct. 20 pencilled in as a potential date for his return. Lazio has made a solid start to its Serie A campaign, having won three and lost two of the opening five fixtures, and the club sits sixth in the league.
Klose, 35, has found the target once in his four games, and Lazio will be keen to have him available soon to boost their striking options.
The Rome outfit visits Sassuolo on Sunday, which will be buoyed by gaining their first point of the season in a 1-1 away draw with high-flying Napoli on Wednesday after having been thrashed 7-0 by Inter the weekend before.