Arsenal's thumping 5-1 win against Crystal Palace on Saturday was marred by an injury to Bukayo Saka.
Saka was forced off with a hamstring issue in the first half and Mikel Arteta said he is "pretty worried" about the winger, who left Selhurst Park on crutches.
That injury blow comes as Arsenal were getting Riccardo Calafiori back after injury.
But Saka is not the only fresh injury concern for Arsenal ahead of the busy festive period.
Here's the latest Arsenal injury news...
Not only did the winger limp off at Palace, he worryingly left Selhurst Park on crutches.
It is the third hamstring injury that Saka has suffered this season and he will undergo tests in the coming days to learn the severity of his latest setback.
"He felt something in his hamstring," said Arteta after the game. "He couldn't continue. He will have to be assessed. Pretty worried about that one."
Asked how severe the injury is, Arteta said: "It's difficult to do that now. They have tested him inside but very difficult to say how bad it is.
"I'm not sure if it's exactly the same one [that he did earlier this season]. It's in the same leg. He had the third minor injury - I don't know how big this is going to be. But he already had two."
Arsenal host Ipswich at Emirates Stadium on December 27. It would be a surprise if Saka features but it remains to be seen how long he could be out of action for.
Potential return date: Unknown
A surprise omission from Arsenal's matchday squad against Palace was Raheem Sterling.
The on-loan Chelsea winger has struggled for game time in recent months but was handed an opportunity in the Carabao Cup last Wednesday, without really grabbing it with both hands.
But it was still a surprise that he did not make the trip to south London, with Arteta revealing his absence was injury related.
"Raheem unfortunately we lost him yesterday, he felt something in training and had to come off and we need to explore that with more tests," Arteta said before kick-off at Selhurst Park.
Sterling would be a contender to fill in on the right hand side if Saka's injury is serious but he has to recover from his own knock first, so a lot depends on those test results.
Potential return date: Unknown
Ben White underwent minor knee surgery in November and, while Arteta issued a positive update towards the end of that month, his return date remains unclear.
"The surgery went really well, there is no reaction after that," he said.
"He is improving day by day but it is a process for the first four to six weeks, where we have to be really cautious and don't put any stress on that knee.
"Then we will see how quickly he can recover and how it reacts after that."
Potential return date: Unknown
Takehiro Tomiyasu has played only six minutes this season due to injury having suffered a setback in his recovery from a knee problem in October.