Newcastle United are bracing themselves for an approach for striker Obafemi Martins as speculation mounts that Manchester United may seek cover for the injured Wayne Rooney.

The 22-year-old is one of a number of frontmen to be linked with the Premier League champions, who have taken just two points from their first three games.

United have scored only one goal - Paul Scholes's strike at Portsmouth - to date this season and with Rooney out for around seven more weeks with a fractured metatarsal and Louis Saha struggling for full fitness, manager Sir Alex Ferguson  is being tipped to invest once again in an effort to plug the gap.

Martins, along with Bolton's Nicolas Anelka and Tottenham's Dimitar Berbatov, has been touted as a potential target and the fact that the Nigeria international has a £13 million release clause in his contract at St James's Park means the Magpies would be powerless to prevent him leaving the club.

Martins scored 17 goals in his first season on Tyneside after making a £10m switch from Inter Milan last summer, and already has two to his name this time around after claiming a double in the 3-1 opening weekend victory at Bolton.

However, Ferguson insisted in the wake of Rooney's injury there would be no panic buying, and even if his stance has altered after his side's dominance failed to yield tangible results in the 1-0 derby defeat at Manchester City on Sunday, Martins may not fit the bill.

The feeling in the north-west is that if Ferguson does decide to return to the market, he will look for a taller and more robust striker than the diminutive and pacy Newcastle man, a template for which either Anelka or Berbatov would be a better fit.

Martins is one of four frontline strikers at St James's - along with Michael Owen, Mark Viduka and Shola Ameobi - while Alan Smith made his name as a forward at Leeds.

Andy Carroll has been sent out on loan to Coca-Cola Championship side Preston, while £9.5m signing Albert Luque has slipped further down the pecking order.

The 29-year-old former Deportivo la Coruna player has been tracked by Spanish side Levante this summer, and a trio of Dutch clubs are also monitoring his situation.

PSV Eindhoven - who failed in a bid to tie up a loan move in January - Feyenoord and Ajax have all inquired about Luque, although his £60,000-a-week wage packet could prove a major stumbling block.