Newcastle head coach Steve Bruce has revealed striker Andy Carroll has suffered a setback in his bid for fitness.
The 31-year-old has managed just 14 appearances to date this season and has been out since the middle of January with a troublesome hip problem.
Speaking to Sky Sports News ahead of Newcastle's game at Arsenal on Super Sunday, Bruce said: "It's disappointing and frustrating for us all because his ankle was the main concern for everybody at the start of the season.
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"He jumped for a ball against Everton a few weeks ago and we've not been able to get him right and just when we think we've turned the corner with it unfortunately he's suffered a setback.
"So it's frustrating for him I'm sure and for all of us but we'll just have to try and get him right as best we can.
"He has to stay positive of course which is frustrating for him because he was just getting himself to a level where we all want him to be again."
Carroll re-joined his first club on a pay-as-you-play deal in August last year as he continued to work his way back from ankle surgery, but has been unable to have the impact on the pitch both he and Bruce would have hoped for because of fitness struggles.
"There was a time just before Christmas when we were looking and he'd made a few assists and started a few games, and that was exactly why we brought him into the club," said Bruce.
"Unfortunately, he's picked up this injury, which is frustrating because all of a sudden, it's drifted into five, six weeks when we expected it to be 10 days.
"I'm sure he's as frustrated as we all are, but unfortunately he's got to try to get fit and hopefully he'll be ready in a couple of weeks, or whenever it will be.
"We're not putting a timescale on it. It's just the way it is."
Bruce has had to deal with a succession of injuries to his forwards this season but he is buoyed that by news that a rib injury Joelinton sustained in the 3-2 victory at Oxford in the FA Cup fourth round is not as bad as first feared.
"It was a knock, no fracture so all okay," he added.
"He trains every day, he plays every day, he scored a good goal against Oxford.
"People will be cynical and say it was only against Oxford but he's made one and scored one
"He's only a young lad and I'm sure he will still progress. The one thing you can't level at him - he never shies away from it.
"He picks himself every day and there are signs of improvement and signs of him getting used to playing in England which can only be a good thing."