Alex Oxlade-Chamberlain has suffered a setback in his recovery from a muscular injury and, according to Arsène Wenger, the midfielder faces a make-or-break period between now and the beginning of next week that will determine his prospects for the remainder of the season.

Wenger has already ruled Oxlade-Chamberlain out for at least two more weeks but the Arsenal manager said he can only hope the problem does not prove to be long-term. The 21-year-old suffered a grade one hamstring tear in the FA Cup win at Manchester United on 9 March and was ruled out for three to four weeks. However, Wenger said the player had now felt discomfort in the groin.

Oxlade-Chamberlain has suffered from groin trouble since the Christmas period and after coming off in the Premier League win at Manchester City in January he missed the club’s next six matches.

“Oxlade-Chamberlain is not available for the next two weeks at least,” Wenger said. “He will not be available for the Burnley game on Saturday and he will not be available for the semi-final of the FA Cup against Reading next Saturday.

“It is taking a bit longer than I thought because he has a groin inflammation. 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, so 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 any more. It is groin inflammation.”

Oxlade-Chamberlain has enjoyed a fine season and there is frustration at his current condition. However, remarkably by Arsenal’s standards, he could be their only absentee from the league visit to Burnley, in which Wenger’s team will seek to maintain their excellent form. They have won 15 of 17 matches in all competitions.

Jack Wilshere, Mikel Arteta, Mathieu Debuchy and Abou Diaby are available again after long-term injuries while Laurent Koscielny and Wojciech Szczesny face fitness tests. It leaves Wenger with rare selection luxuries to further the feel-good factor at the club. Wenger is happy at how the team has looked better balanced since the turn of the year and how they are hitting their stride at the right time, even if it appears to be too late for them to win the title.

Not for the first time Wenger talked up the importance of balance, particularly in terms of the average age of a squad. Manchester City, for example, are looking to bring more youth into their ranks this summer and they have been linked with a move for Wilshere, the 23-year-old midfielder, but Wenger said there is no chance of that happening.

The Frenchman added: “When all your main players get close to 30, you can’t buy a 30-year-old player. You have to buy a player who is 22 or 23 because if you buy another player of 30, they all die together. As a manager, in the long-term and short-term, you have to say: ‘OK, we can win the league’ but you cannot go without planning for the future. So the players we buy this summer have to be a bit younger – they cannot be 29 or 30. Age-wise you need a balance.”