The 28-year-old former Arsenal footballer, according to Midtjylland, is “suffering from what appears to be an acute brain-related illness”.
The Danish team declared on February 20 that he was admitted to Aarhus University Hospital.
According to Midtjylland, there have been “growing rumors and speculation about Kristoffer Olsson’s recent absence,” which obliged them to issue an update.
“Kristoffer’s unexpected illness has obviously had a profound impact on everyone at FC Midtjylland,” the team stated in a statement on Tuesday.
“Kristoffer Olsson is afflicted with an apparent acute brain-related sickness that isn’t brought on by any external stimuli or self-harm of any kind.
“A team of leading Danish medical experts are currently working under pressure to make a diagnosis and initiate the correct treatment.”
After graduating from Arsenal’s development academy, Olsson played just one game for the Gunners before making a permanent move to Midtjylland in the middle of the 2014–15 Premier League season.
On what was once known as Twitter, Arsenal posted on X, saying, “Kristoffer, get well soon. We hope you heal completely and quickly.”