Newcastle United fear that Dwight Gayle is facing another month on the sidelines.
Gayle, the Championship leaders' 20-goal leading scorer, limped off against Aston Villa on Monday night after suffering a recurrence of a hamstring problem.
And Aleksandar Mitrovic is on standby to face Bristol City at St James's Park on Saturday.
Gayle is also likely to miss the away games against second-placed Brighton Hove Albion, Huddersfield Town and Reading as well as the home fixture against Fulham.
"Obviously, a big squad helps," said United manager Rafa Benitez told BBC Radio Newcastle.
"Mitrovic has been good, and Daryl Murphy, with his experience and with his age, has been an example for the young players. I'm really pleased for them
"I'm disappointed now, but maybe we will lose Dwight. Hopefully, it's not serious and still we can have the competition between the three strikers."
Gayle, signed from Crystal Palace last summer, also had a spell out last season with a hamstring injury.
And Benitez took the 26-year-old off as soon as he signalled he had a problem.
"He wasn't comfortable from the beginning," said Benitez, whose side lead the division by a point.
"He said he was feeling something again in his hamstring. We had to make the substitution, because it could be worse.
"We have to wait. We don't know how serious the injury is."
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