Michael Duberry is a major doubt for the start of Oxford United’s npower League Two season after suffering a neck injury during the summer.

The experienced defender is struggling with a prolapsed disc which is expected to rule him out of training for a month.

Duberry first became aware of a problem shortly after the end of last season, when he woke up with pins and needles in one of his arms.

After a thorough medical check the 36-year-old received an injection earlier this summer.

But it failed to clear up the problem and another injection was recommended last week.

The diagnosis in itself should not give cause for alarm.

United physiotherapist Andy Lord said: “It’s unusual for one injection to totally get rid of the problem, so it was likely he was going to have a second one.

“It’s an occupational hazard – after heading thousands of balls over 20 years you get wear and tear.”

It will be at least another week before the impact of the second injection can be assessed.

But even if it is successful, Duberry is unlikely to be given the all-clear to return to training until next month at the earliest.

It is a significant blow to the former Chelsea and Leeds United player, who made 37 appearances last season after signing for the U’s 12 months ago.

United boss Chris Wilder strengthened his defensive options this week with the signing of Michael Raynes, but fellow centre back Harry Worley is not due to return to fitness for another fortnight following ankle surgery in May.

l OXFORD United have extended their sponsorship deal with Bridle Insurance into a third season.