The 22-year-old striker underwent surgery on his injured groin in November last year, but has been struggling with it during his World Cup campaign with Denmark.
“I still feel quite bad in my groin,” he told the Daily Mirror. “And that worries me a lot.
“Sadly it hasn’t been better during my holiday, like I expected it to giving it nothing but rest.
“I had hoped and counted on that a total break from football and training would heal the injury but it hasn’t happened.
“I have spoken to Arsenal throughout the holiday and I am having a big scan when I return this week.
“My whole body must be scanned to find out where the groin problem really comes from.
“I still feel pain and it is very frustrating. I don’t know where I am in relation to playing football.”