NEWCASTLE chairman Freddy Shepherd will step up his search for Sir Bobby Robson's successor this morning, with skipper Alan Shearer holding the key to his decision.

Shepherd will consult with the rest of the United board as he weighs up his options in the light of Robson's dismissal - but first he must decide how Shearer fits into his long-term plans.

The Newcastle captain will hang up his boots at the end of the season, and is already well on the way to achieving the UEFA qualifications he needs to lead the Magpies in the Premiership.

Shearer revealed that he is considering a career in management earlier this year, and the native North-Easterner would jump at the chance of taking over at St James' Park in the future.

There is no chance of the 34-year-old being handed the reins on his own at the moment but, if Shepherd envisages him leading United in the next 18 months, he will have to solve the current managerial puzzle with that in mind.

Sources close to the club suggest that Shepherd is keen to give Shearer a prominent coaching role in the new managerial set-up, with a more experienced hand working alongside to show him the ropes.

But such an arrangement would severely limit United's choice of manager, as few senior figures within the game would be willing to tutor someone who would eventually dethrone them.

The names of Terry Venables and Gerard Houllier have been put forward as potential tutors for Shearer, with both commanding respect because of their coaching abilities.

Venables enjoys a close relationship with Shearer, and the pair worked together effectively as England reached the semi-finals of Euro 2004.

The former Tottenham, Barcelona and Leeds boss has succeeded in a similar arrangement before, steering Middlesbrough to Premiership safety in the company of Bryan Robson in 2001.

Earlier this month, former Newcastle centre-half Jonathan Woodgate described Venables as the best coach he had ever worked with and, despite struggling in his last job at Elland Road, the former England boss remains highly rated within the game.

The same is true of Houllier, despite his six-year reign at Liverpool ending acrimoniously this summer.

Houllier established a reputation for innovation by establishing the French football academy at Clairefontaine that is continuing to produce a stream of world-class youngsters.

He failed to guide France to the 1998 World Cup and was criticised for a succession of poor signings at Liverpool, but is still seen as one of football's foremost thinkers.

Significantly, he also tried to take Shearer to Anfield in the summer of 2003 and could be persuaded to work alongside the striker over the next nine months.

It is difficult to see any of the other prospective candidates for the manager's job agreeing to such an arrangement, but Shepherd could opt to go in a totally different direction anyway this week.

While the United chairman is keen to see Shearer managing the Magpies in the future, he may decide that his long-term plans have been overtaken by the club's need for short-term stability.

Newcastle are already ten points behind Premiership leaders Arsenal and Chelsea and, when a similar gap opened up last season, they were unable to claw their way back into a Champions League spot.

Shepherd is known to be alarmed at the prospect of history repeating itself, and other members of the United board are believed to be keen on making sure they have the best man to ensure that doesn't happen, regardless of what that means to Shearer's future ambitions.

Birmingham manager Steve Bruce has long been talked of as a future Newcastle manager, although the Blues have already confirmed that they will fight tooth and nail to hold onto their boss.

Bruce's Geordie roots are an obvious attraction, while the former Manchester United centre-half has proved at St Andrews that he can mould a team that is obdurate and hard to beat, values that have hardly been attributable to the Magpies in recent years.

He is not the kind of big name that would get Newcastle's fans purring but, after the failures of Kenny Dalglish and Ruud Gullit, the club's board are unlikely to see that as a priority.

Martin O'Neill would be a more popular choice but, with Celtic looking ahead to Champions League games against Barcelona and AC Milan, United could struggle to persuade the Irishman that he would be taking a step forward by moving to Tyneside.

O'Neill is also understood to covet the Manchester United job, and Newcastle would be loath to employ someone who could jump ship for Old Trafford were Sir Alex Ferguson to call it a day.

Gordon Strachan is currently out of employment after leaving Southampton last season, while Steve McClaren's name is inevitably mentioned when any high-profile vacancy comes around.

But, ultimately, Shearer will play the pivotal role in determining who succeeds Robson.

Read more about Newcastle United FC here.