Oxford United striker Marvin Robinson will today find out the extent of his knee injury.

The 26-year-old undergoes exploratory surgery on his right knee after picking up the injury in the televised win over Crawley last week.

It could mean a spell of between ten and 12 weeks on the sidelines for Robinson, who is yet to score for the U's since his move from Macclesfield a month ago.

The forward played on with the injury, not realising how serious it was until a preliminary scan showed the damage.

United physio Neil Sullivan said that it was a case of keeping fingers crossed and hoping for the best.

"We know that Marvin had done damage to the posterior cruciate ligament in his knee," he said.

"The scan shows that there are fibres still intact which is a good thing.

"It is a case now of hoping that there are plenty of them intact.

"I would say that you are probably looking at between ten and 12 weeks, but it is very difficult to tell for sure until he has had this operation and we know the damage."

There is good news on United's injury front however, with Gavin Johnson making good progress from his hamstring injury.

The left wingback was originally thought to be sidelined for a minimum of six weeks, but is making good progress and is ahead of schedule.

Sullivan explained: "Gavin is running again, but is suffering a bit from a stiff back because of the break he has had.

"That is holding him back a bit, but although he can't sprint yet, he can at least do all of his other fitness work so is in good shape.

"If everything goes well, I would think he may be back in around two weeks, but again it's a case of waiting and seeing.

"He would be looking for a reserve game in around a fortnight to get back into the swing of things.

"The problem is that reserve games are very unpredictable - sometimes there is about a month between them so we'll just have to see if there are any at the right time for him.

"But he is making good progress and is ahead of schedule which is obviously good news."