When Mikel Arteta released his team sheet for Arsenal's Europa League quarter-final second leg, the name of Pierre-Emerick Aubameyang was conspicuous by its absence.
Needing goals away to Slavia Prague, the Gunners were without a striker who'd found the net for them on 14 occasions this season.
Aubameyang had also missed last weekend's 3-0 Premier League win against Sheffield United through illness. Asked about his and Martin Odegaard's availability in Prague, Arteta replied, "I don’t know we have to see today how they are".
When Aubameyang's name was again absent from the squad on Thursday night, eyebrows were again raised.
Minutes before kick-off, the 31-year old revealed the surprising reason for his lack of availability.
"Hey guys," he wrote on Instagram, seemingly from a hospital bed, "Thanks for all the messages and calls.
"Unfortunately I contracted Malaria whilst being on national team duty in Gabon a few weeks ago.
"I’ve spent a few days in hospital this week but I’m already feeling much better every day, thanks to the great doctors that detected and treated the virus so quickly.
"I wasn’t really feeling myself the last couple weeks but will be back stronger than ever soon! Will be watching my boys now, huge game for us! Let‘s go and get it Arsenal!"
It's not yet known when Arteta can expect to have Aubameyang fit again.
The Newsround | Social media and sport | Scott Fardy retiring this summer