Kevin Keegan could become the victim of his own bad planning after Alan Shearer yesterday became a major injury doubt for England's opening European Championship game against Portugal on Monday.

The captain underwent a scan on his damaged knee yesterday and will not resume training until at least tomorrow.

Shearer hurt the knee falling awkwardly in the friendly against Malta last Saturday. But the question is why he was risked in the first place, because yesterday he admitted that he had a "slight niggle" in his knee going into the game.

As the match was largely a flagwaving exercise Shearer's presence was hardly mandatory, especially as he had played in the previous two friendlies against Brazil and Ukraine. By starting him Keegan not only risked aggravating the "niggle" but also missed an opportunity to try out a different strike partnership as a fail-safe should he have to do without Shearer.

Now Keegan faces the prospect of going into the tournament with a rookie international strike-force, comprising Michael Owen with either of his Liverpool team-mates, Emile Heskey or Robbie Fowler.

Fowler has been struggling for match fitness after a lengthy injury lay-off. The only other striker in the squad is the newcomer, Kevin Phillips.

The 29-year-old Shearer, who is due to retire from international football after Euro 2000, last scored for England seven games ago.

The injury has proved worse than first thought. When Shearer did not train on Wednesday Keegan insisted: "Alan Shearer will train tomorrow. He is fine. At a push he could have trained today." But the Newcastle striker did not train yesterday and instead underwent a scan on his knee before flying out to the squad's base in Belgium.

The situation has uncomfortable echoes of Andy Cole's exit from the squad. He was deemed "fit" after visiting a specialist only to be ruled out a couple of days later.

Keegan has until Monday's deadline to decide if he wants to bring a replacement for Shearer into the squad.