Middlesbrough defender Matthew Bates will see a specialist in the coming days to assess the extent of the damage done to his knee in a weekend friendly at Carlisle.
The 22-year-old tore the anterior cruciate ligament in his left leg midway through the first half on Saturday.
Bates, who has been with the club since he was 12, will visit an orthopaedic surgeon in London either later this week or early next once the swelling around the injury has gone down.
The centre-back, who signed a three-year contract extension a month ago despite being linked with Wolves, Wigan, West Ham and Fulham, has already had three cruciate ligament operations in his relatively short career.
"It's terrible news for Matthew and our thoughts are with him," manager Gareth Southgate told the Middlesbrough Evening Gazette.
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