The former Arsenal star believes the Gunners could be in trouble if Olivier Giroud picks up an injury, with few alternatives to the French striker available to Arsene Wenger.
Parlour, who made more than 400 appearances for Arsenal in all competitions, joined the list of pundits praising the club for signing Real Madrid star Mesut Ozil on transfer deadline day.
Ozil, who cost a reported 42 million pounds, will strengthen Arsenal significantly, according to Parlour, but he still has doubts over whether Wenger has enough top-class strikers at his disposal.
"I'm worried about the forward line," Parlour told The Daily Star. "Giroud was excellent against Spurs.
"But if he does get a niggle or gets injured, then the next player that can play there is Theo Walcott because Lukas Podolski is out injured.
"It's the only position I am worried about. If Giroud does get hurt, they are going to be light.
"They got Ozil in – great. But could they have signed a striker as well?"
Giroud has started the 2013-14 season in excellent form, scoring in all three Premier League matches Arsenal have played. After an opening day loss to Aston Villa, Arsenal rebounded with wins over Fulham and rival Tottenham as it climbed to fourth in the table.