The Buffalo Bills have suffered a second blow to their pre-season preparations with the news that Percy Harvin will be out for two weeks, according to reports.

The 27-year-old limped out of practice on Tuesday with a hip injury and was given an injection.

However, coach Rex Ryan said that he has not responded to the treatment, and NFL Media claims that he may not be fit until the final week of pre-season.

Ryan told reporters: "He's so itching to get back, that that's why we sped it up. We were going to wait four days to give him the shot. We gave it to him early. Hopefully he responds on it."

Harvin moved to the Bills along with Ryan from the New York Jets.