Alex Oxlade-Chamberlain was wearing a protective boot and on crutches as Liverpool lifted the FIFA Club World Cup trophy.
The England international midfielder landed awkwardly 72 minutes into Liverpool's 1-0 extra-time win against Flamengo, and was clearly suffering pain in his right ankle.
A stretcher was brought over to help assist Oxlade-Chamberlain off the pitch, but he eventually walked off on his own accord as he was replaced by Adam Lallana.
The injury adds to Reds manager Jurgen Klopp's midfield concerns, with Georginio Wijnaldum and Fabinho currently unavailable with hamstring and ankle problems respectively.
Oxlade-Chamberlain was previously out for a year, missing all but two matches in the 2018/19 season, after suffering knee ligament damage in the Champions League semi-final against Roma.
However, he has been in good form for Liverpool this campaign, with six goals in 24 appearances across all competitions.
The Reds eventually become the world champions after Roberto Firmino's winner in extra-time secured their first Club World Cup trophy.