Sam Allardyce of Bolton Wanderers and Steve McClaren of Middlesbrough have moved to the centre of Newcastle United's radar as potential replacements for Bobby Robson, who was sacked on Monday.

They do so as Newcastle's chances of securing either of their preferred options, Steve Bruce of Birmingham City or Alan Shearer, disappeared.

Bruce last night issued a statement saying: "I've got a job to do here and I'm determined to get on with it. Newcastle is where my roots are but nothing has changed. I am committed to Birmingham City."

A prohibitive get-out clause at Birmingham, plus a time-delay on his release, stymied the pursuit of Bruce, who has enjoyed sound relations with the Newcastle chairman Freddy Shepherd for some time.

Newcastle had hoped that Shearer would either work with Bruce or go on his own with an experienced figure alongside, but the club have reluctantly accepted that their centre forward wishes to see out his last season at Newcastle purely as a player.

As a result Allardyce and McClaren, who both fit the required Newcastle profile - young, British and disciplined - have attracted interest.

Both, however, have jobs already and are prospering at their clubs. Getting either out of Bolton or Middlesbrough respectively could be difficult, especially the latter given they are local rivals and Shepherd and the 'Boro chairman Steve Gibson are close.

And on a day when circumstances at St James' Park meant Newcastle were unable to recruit a new defender, there are also logistical hurdles with Allardyce and McClaren.

Allardyce is in Spain, though he flew there after the rest of the Bolton squad had departed for a short break.

Spain is hardly the end of the world and a meeting could easily be arranged, though there was believed to be initial hesitancy from Allardyce about the prospect of leaving Bolton.

In his renewed capacity as Sven-Goran Eriksson's full-time coach, McClaren travels to Austria and Poland with the England party for World Cup qualifiers on Saturday and Wednesday, although England do not leave until tomorrow morning.

That timetable provides McClaren, Newcastle and 'Boro with obstacles, but they are not insurmountable.

Newcastle have 10 days before their next fixture, at home to Blackburn Rovers, and the club will be vilified by supporters should there be no manager in place by then. They are undoubtedly reaping the consequences of failing to dismiss Robson in the summer, though by then they had clearly lost faith in his powers.

Yesterday Shepherd came close to revealing the true reason why he did not act sooner: "I didn't want to be known as the man who shot Bambi," he said.

Shepherd also said: "It was a tough decision to part with SirBobby - one of the toughest I"ve had to make. We spoke of our admiration for the man . . . when we announced the decision, and it is very upsetting when you part company with a great guy like Bobby. But in situations like this there is no room for sentiment."