Dimitar Berbatov has suffered an injury blow while playing for Bulgaria and is now a doubt for Manchester United's Aston Villa trip on Saturday.

The 27-year-old striker lasted only 30 minutes in his country's 6-1 defeat to Serbia before he limped off holding his hamstring.

Berbatov will undergo assessments with United's medical team and, if it is his hamstring, it is most likely that he will be absent for the clash at Villa Park.

Meanwhile, United manager Sir Alex Ferguson will be boosted by the news that Berbatov plans to quit international football, as his agent claims the player is being made the scapegoat for his national side's poor form.

"Dimitar said to me that, because people blame him for Bulgaria's bad performances, he is ready to quit the national team," said Emile Dantchev.