"We will see how it goes from day-to-day", Germany coach Joachim Loew told reporters.
Germany have announced their 35-man preliminary squad for the 2018 World Cup. Loew opts for Petersen over Bayern Munich forward Sandro Wagner.
Injured Manuel Neuer was named in Germany's extended 27 man pre-World Cup squad on Tuesday, but there was no place for Brazil 2014 victor, Mario Goetze.
Bayern Munich goalkeeper Manuel Neuer has been named in the provisional squad, despite being out of action since breaking his foot in September.
"We were in constant communication", Low said. He's now taking a full part in training in Munich.
Neuer must now prove his fitness at a fortnight-long training camp in northern Italy, which starts on Tuesday. "But you can not go into such a tournament without match practice".More news: India threatens to take Nawaz Sharif's statement to ICJ
The 32-year-old Neuer suffered a broken bone in his foot and only returned to training days ago but Germany coach Joachim Loew made a decision to take four keepers to the training camp in the Italian Alps from May 23-June 5.
Low instead selected Stuttgart's Mario Gomez and uncapped Freiburg striker Nils Petersen, who scored 15 league goals this past season - a record eight as a substitute and five from the penalty spot.
The 32-year-old could make a high-profile return in Bayern's DFB-Pokal showdown with Eintracht Frankfurt on Saturday, while Germany have scheduled pre-tournament friendlies against Austria and Saudi Arabia.
"He got 15 goals with a team that does not create many goal chances". "I have always said that for me Joachim Loew is the best coach for the national team".
He led Germany to a victory at the 2014 FIFA World Cup in Brazil and the 2017 FIFA Confederations Cup in Russian Federation. "He did not show what his qualities are".