RYAN SHOTTON will undergo a series of tests to ascertain the full extent of the knee injury that kept him out of Middlesbrough’s goalless draw with Rotherham United.

Shotton was unable to feature in last night’s game after complaining of pain in his knee, and Tony Pulis admits the full-back was missed as Boro failed to score for the third home game in a row.

At this stage, Boro’s medical staff are still to confirm the extent of the damage to the 29-year-old, but he is already regarded as a doubt for Saturday’s televised home game with Derby County.

There is a chance the problem could sideline Shotton for a number of weeks, with the situation set to become much clearer over the next couple of days.

Pulis said: “Ryan’s got a sore knee. I thought we missed Ryan (against Rotherham), so we’ll have to see how long he’s going to be out for.”

When asked whether the injury was serious, the Boro boss added: “We’re not sure yet, but we’ll soon find out.”