OXFORD United are sweating over news of Sam Winnall’s hamstring injury.

The striker was forced off late on in Tuesday’s 2-0 defeat to Crewe Alexandra, leaving the U’s to finish the game with ten men.

He went for a scan yesterday and the severity of the problem is likely to be discovered today.

Boss Karl Robinson did not want to speculate for how long Winnall could be sidelined, but was not optimistic.

He said: “There’s no timescale, but he’s still very sore.

“You get a decent indication that you know it won’t be a quick one.”

United had been carefully managing Winnall’s return to action, after he had been troubled by niggles since signing in September.

It was a move which at the time looked an excellent one, providing the former Sheffield Wednesday front man could stay fit.

He had not played since January and only managed 25 appearances in the previous two seasons.

Robinson felt the manner of the injury was difficult to guard against, but it is another blow in a campaign which was supposed to be based around Winnall and Matty Taylor leading the line.

He said: “I think it’s not about me saying ‘Sam could have done this, we could have done that’.

“He’s done it jumping for a header. It wasn’t a sprint, it wasn’t fatigue.

“It’s frustrating though because you feel you have two strikers who can really put a dent in the league and one of them hasn’t started in the league, which is incredibly disappointing.”

He added: “When he came on (against Crewe) he showed the real quality he has.

“He won every header and the two centre backs knew they were in a game.

“He’s a Championship striker that’s dropped down to try to get back there.

“We’re going to be missing a very good footballer.

“It was evident on Tuesday what he brings to the team.

“We’ve been seeing that on a daily basis since he’s been back fit, so it was a bit of a kick to us when he had to come off.”