Arsenal full-back Hector Bellerin could miss the start of next season after rupturing knee ligaments in Saturday's Premier League win over Chelsea.
Bellerin went down unchallenged during the second half of Arsenal's 2-0 victory and was carried off on a stretcher, with the club confirming he could miss up to nine months after undergoing surgery to repair the damage.
The 23-year-old was making his first start since mid-December having overcome a calf problem, but will now miss the remainder of the season, and possibly the start of the 2019/20 campaign.
Arsenal revealed the severity of Bellerin's injury with a short statement on their website.
"Further to the injury sustained during our match against Chelsea on Saturday, we can confirm that Hector has ruptured the anterior cruciate ligament of his left knee," it read.
"Hector will undergo surgery to repair this in the coming days. The rehabilitation process is expected to take between six to nine months and therefore rules Hector out of action for the remainder of this season.
"Everyone at the club will now be working as hard as we can to ensure Hector is back on the pitch as soon as possible next season."
The Spain international then posted a message on Twitter, along with pictures of the brace on his knee, which read: "There are no obstacles in life you can't get over. Been a difficult couple of days but I'm positive and ready to take whatever challenge comes my way. Thank you so much for the love and messages, you are incredible."
Bellerin's Arsenal team-mate Rob Holding suffered a similar injury in a 2-2 draw at Manchester United on December 5.
While the January transfer window would allow Arsenal to bring in cover at right-back, Emery does have options in Stephan Lichtsteiner, Ainsley Maitland-Niles and Carl Jenkinson, who was expected to be allowed to leave the Emirates Stadium this month before Bellerin's setback.
The injury is more bad news for Arsenal, who announced on Monday that head of recruitment Sven Mislintat would be leaving the club next month, a little over a year after taking the role.
Although the victory over London rivals Chelsea takes Arsenal to within three points of the fourth-placed Blues in the table, Emery confirmed recently that there was no money available to improve the squad and that any January arrivals would be restricted to loan deals.
Barcelona attacking midfielder Denis Suarez, who played under Emery at Sevilla, continues to be linked with a move to rejoin his former coach, while Yannick Carrasco and Ever Banega are also reported targets.
ga('create', 'UA-72310761-1', 'auto', {'name': 'pacontentapi'});
ga('pacontentapi.set', 'referrer', location.origin);
ga('pacontentapi.set', 'dimension1', 'By Mark Mann-Bryans, Press Association Sport');
ga('pacontentapi.set', 'dimension2', '9212e3f7-0d04-42f8-9e51-f0880046d355');
ga('pacontentapi.set', 'dimension3', 'paservice:sport,paservice:sport:club-news,paservice:sport:football,paservice:sport:uk,paservice:sport:world');
ga('pacontentapi.set', 'dimension6', 'story');
ga('pacontentapi.set', 'dimension7', 'composite');
ga('pacontentapi.set', 'dimension8', null);
ga('pacontentapi.set', 'dimension9', 'sport:football');
ga('pacontentapi.send', 'pageview', { 'location': location.href, 'page': (location.pathname + location.search + location.hash), 'title': 'Arsenal\u2019s Bellerin facing up to nine months on sidelines with knee injury'});