The striker limped out of Friday night's friendly defeat to Hertha Berlin in Palma after pulling his hamstring, and is a huge doubt for the opener away to Manchester United on August 17.

Ameobi – who could yet leave St James's Park this summer – hopes his quick withdrawal has minimised the damage, and Keegan's staff will see how the injury has settled down early next week.

The 26-year-old is one of a number of strikers unavailable to Keegan for tonight's game against PSV Eindhoven at St James's Park, though Michael Owen and Obafemi Martins are expected to play some part in Saturday's home friendly against Valencia after recovering from their respective calf and knee injuries.

Keegan said: "It's a little bit disappointing for Shola.

"He's worked very, very hard in pre-season, his first in three years.

"He's got a slight problem with his hamstring.

"It's a setback, but at least it's happened this time of year.

"It's a shame, because he has worked really hard.

"In a week, we'll assess it. Hopefully he'll be back in light training in a couple of weeks."

A number of clubs are interested in Ameobi, who ended last season on loan at Stoke City.

However, so far no-one has met Newcastle's valuation of the striker, thought to be around £3m.