The England international could face an operation if he fails to recover before the end of Arsenal's season.
The Frenchman is quoted by the Mirror as saying the club will monitor the injury for the next two weeks, but that the youngster's recovery has already taken longer than expected.
“It is taking a bit longer than I thought because he has a groin inflammation," said the Gunners boss. "It is related to everything before.
“I hope it does not become a long-term problem, but he faces a hurdle this week in training. We will see if he has recovered well.
“The end of this week and the start of next week are important to see if he got rid of that inflammation. It is not his hamstring anymore. It is groin inflammation.”
Oxlade-Chamberlain's time at Arsenal has been punctured by injuries frequent enough to stop him building on his exciting potential.
He hasn't managed to make more than 25 league appearances in any of his four seasons at the Emirates, and the England man may have thought this year would be the time when he broke that record, with 22 outings so far.
But after suffering an injury in the FA Cup win over Manchester United last month, Oxlade-Chamberlain's availability for Arsenal's remaining games looks like being very much diminished.
The Mirror report that Arsenal's medical staff, who have had to deal with numerous injuries over the last two years, are confident the 21-year-old will be able to play again before the end of the season, but things will be clearer over the next couple of weeks.
If Oxlade-Chamberlain doesn't improve in that time, they may end up deciding an operation is the best course of action.