Alan Shearer's season is on the line following the third - and final - injection in his problem knee.

The 30-year-old Newcastle striker, out for the last two games, may need an operation if the latest steroid treatment proves unsuccessful.

That would force him on to the sidelines for about three months, leaving manager Bobby Robson with a massive headache in a season which is threatening to turn sour.

Newcastle coach Mick Wadsworth said yesterday: "Alan has had the injection and we are waiting to see if there is any reaction."

Robson is likely to be given the verdict this morning, making it D-day for United as they enter a vital month.

The Newcastle boss is already without his other first-choice striker Carl Cort and is finding it difficult to persuade the United board to finance another major deal.

However, Robson is hopeful that the injection will again do the trick and Shearer himself is optimistically eyeing a return against Bradford City on Saturday

That would be a massive boost for Robson, who saw how his side collapsed dismally without Shearer's influence at Arsenal last Saturday.

Shearer has already had two injections to deal with tendinitis in his knee, including one which got him through Euro 2000.

There won't be a fourth injection and specialists have told him they will look for another solution if the latest treatment proves unsuccessful. Newcastle will face a dilemma over the best course of action if the problem doesn't clear up.

Shearer could be ordered to rest for the next few weeks to see if the tendinitis disappears - but, if that's not the answer, the delayed operation could keep him out for the remainder of the season