Eric Bailly was stretchered off after "twisting his knee" in Manchester United's 2-1 win over Tottenham at the Hongkou Stadium in Shanghai.
Bailly was brought on at half time in Thursday's International Champions Cup match, but pulled up with the knee problem just nine minutes after coming on as he tried to keep Heung-Min Son from scoring.
Speaking to MUTV after the victory, United manager Ole Gunnar Solskjaer said: "It seems he has twisted his knee so we've just got to do some scans and checks on him.
"At first sight it does not look great, but let's wait and see."
Pictures have emerged of the defender leaving the stadium on crutches in a knee brace after the 2-1 victory.
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The 25-year-old centre-back had only recently returned from a medial ligament injury which he suffered against Chelsea in April.
Bailly was forced to miss the Ivory Coast's Africa Cup of Nations campaign due to the problem.
After missing United's opening pre-season game against Perth Glory in Singapore, Bailly featured in their next two matches against Leeds and Inter Milan.
In the match against Spurs, Anthony Martial put United ahead 21 minutes in after beating goalkeeper Paulo Gazzaniga at his front post. But the scores were levelled up by substitute Lucas Moura's deflected shot which wrongfooted Sergio Romero.
United fought back late in the second half and found a breakthrough with academy graduate Angel Gomes scoring his first senior goal for the club, making it 2-1 with 10 minutes to go.