The 21-year-old, who had just returned to the side following a groin problem, was substituted during the second half of Monday night's FA Cup quarter-final win at Manchester United, where he had earlier set up Nacho Monreal's opening goal.
Manager Arsene Wenger confirmed the midfielder was set for a scan but the prognosis would not be determined until later in the week, although it is now unlikely Oxlade-Chamberlain will feature in Saturday's Barclays Premier League game against West Ham.
"Chamberlain has a hamstring strain, the only thing we don't know is how bad it is because usually the scans are only done 48 hours after the accident
That will be done today [Wednesday]," Wenger said in an interview with the club's official website, www.arsenal.com.
Wenger added midfielder Jack Wilshere was "progressing well" following minor surgery to removes studs from pins in his ankle, and Mathieu Flamini had resumed full training after a hamstring problem, so comes into contention for Saturday.
There was also positive news on centre-back Gabriel Paulista, who limped off against QPR with a hamstring strain but is expected back training "on Sunday or Monday".
Wenger believes the victory at Old Trafford, secured by a goal from former United striker Danny Welbeck, can have a positive impact for the remainder of the campaign.
The Gunners boss, though, accepts recent performances have drained his squad physically, and so will have some decisions to make as he looks to keep the players fresh for both the West Ham match and the second leg of their Champions League tie at Monaco, where Arsenal will be out to overturn a 3-1 deficit.
Theo Walcott could come back into contention, having again been left on the bench at United.
"We were at a high level of fatigue because we played against Monaco, Everton, QPR, Manchester United, all very physical games," said Wenger.
"I will have to test medically, physically, how the players are on Friday, and I will make my decision then
The big priority is of course West Ham."
German forward Lukas Podolski, meanwhile, has indicated his intention to return to Arsenal in the summer, having failed to make an impression on a loan spell at Inter Milan.
Speaking to Sport Bild, the World Cup winner said: "The chapter is not closed with Arsenal, because there is no purchase option.
"I was the first person to clear things up in the talks with Inter and say I didn't want any kind of clause that would have let them purchase my contract rights.
"When you're on loan you never know what can happen, so at the end of the season we'll analyse things freely and decide the situation."
Podolski was left out of Inter's squad for the Europa League and has seen his performance levels criticised by Nerazzurri coach Roberto Mancini.
The 29-year-old added: "At Inter there have been some negative situations, but I see the bright side in all of it.
"Also, it's generally easier to criticise someone who comes on loan, as I did this winter."
Arsenal are set to join Everton, Stoke and a Singapore Select XI team for the Barclays Asia Trophy Singapore in July 2015, which will see the Gunners return to the country for the first time since 1991 as part of their pre-season campaign.
Wenger said: "It will be a typical English Premier League competition in Asia and we know that English football is very popular in Asia, and that's a good opportunity to show how much we respect Asia as well.
"[Strong competition] is what you're looking for, to prepare well with the right intensity in the games to have a look at everybody as well
We have young promising players who can be a name after the competition
It's a good opportunity as well for Singapore people to see these players."
Source : PA
Source: PA