Manchester United's record signing Rio Ferdinand limped off during their pre-season friendly with Argentina's Boca Juniors this afternoon.
Ferdinand, at Stg£29 million the world's most expensive defender, clutched his left ankle following a challenge after 30 minutes and was replaced by Waterford’s John O'Shea.
The 23-year-old England defender was helped off the pitch, although the seriousness of the injury was unclear.
Initial reports claim he has suffered a twisted ankle and is doubtful for United's Champions League third round, first leg qualifying tie against Hungary's Zalaegerszeg on Wednesday.
Ferdinand joined the Old Trafford club from Leeds United earlier this month. United were leading Boca 2-0 at halftime, after two strikes from Ruud van Nistelrooy.
