Arsenal manager Arsene Wenger has revealed Alex Oxlade-Chamberlain could be out for up to eight weeks with a knee injury.
Wenger commented on Sunday that the midfielder would miss "a few weeks" with ligament damage sustained in last Tuesday's Champions League defeat to Barcelona.
And, while scans pointed to a longer lay-off for the England international, Wenger admits it could have been a lot worse, with Oxlade-Chamberlain still in with a shout of earning a spot at Euro 2016.
"We thought there could be some [surgery] when we saw the MRI but we got positive news," he told a news conference.
"The next eight weeks means March, April he will be out. He should be alright [for Euro 2016]."
Wenger also conceded he could now be forced to delve deeper into his squad to cover first-team players who are struggling to cope with Arsenal's packed fixture list.
"It's possible, yes," he added. "Some players are still not completely fit, like Danny Welbeck - medically, I still need advice on that."
Arsenal face Swansea City on Wednesday looking to bounce back from the Barcelona result, as well as a 3-2 Premier League defeat at Manchester United on Sunday.
"Of course we gave a lot against Barcelona and a disappointing result and it had an impact on our belief against Manchester United," he told reporters.
"We want to focus on the positives and recover from that defeat and give our best until the end of the season.
"I don't think we have any [injury] problems from Sunday, apart from one or two [with] muscular tightness, but everyone should be available."
Arsenal are five points adrift of league leaders Leicester City following their loss at Old Trafford, and three off second-placed Tottenham.