Newcastle are sweating on the fitness of Steven Taylor after he picked up a shoulder injury on Saturday.
The centre-half has suffered similar problems in the past, with a dislocated shoulder keeping him sidelined for four months in 2006.
The former England U21 international sustained his latest setback during the 3-0 victory for the Magpies in their pre-season friendly at Carlisle.
He now faces a race against time to work his way back to full fitness in time for the start of the new Premier League season.
Newcastle boss Chris Hughton admits he is unsure as to the severity of the injury, but hopes the situation will become clearer once Taylor has undergone medical tests.
"Obviously we are aware of Steven Taylor's shoulder problems in the past, but we will not know the extent of this one until we can assess it properly in two or three days," he said.
"It's always a worry to have an injury of this sort, especially at the start of the season, but we will just have to wait and see."