Nathaniel Chalobah's England breakthrough will be put on hold after the Watford midfielder suffered a freak knee injury in training.
The 22-year-old who was called into Gareth Southgate's squad last month following his £5m move from Chelsea is on crutches with his knee in a brace.
Watford are refusing to put a timescale on the injury but are sending him for another scan this week after he missed Saturday's 2-1 win at Swansea.
No team-mate was understood to be involved when he suffered the injury at their London Colney base.