Arsenal are fearful that one of their experienced troops could spend weeks on the sidelines with his fresh injury concern, according to a report.
The Gunners restored their seven-point lead at the top of the Premier League table with a 4-0 thumping of Leeds United on Saturday, despite suffering some fresh blows before the game.
Mikel Merino was firstly ruled out before kickoff with a foot injury, before Bukayo Saka appeared to pull a muscle during the warm-up and was replaced at the last minute by Noni Madueke.
Mikel Arteta could not give a firm update on either man at full time, although Madueke excelled in Saka's absence, setting up Martin Zubimendi's opener before scoring direct from a corner.
Meanwhile, Declan Rice, Zubimendi and Kai Havertz started in the engine room with Merino absent, while Christian Norgaard and Martin Odegaard occupied places on the bench at Elland Road.
Arsenal have serious 'fear' over Mikel Merino foot injury
While Arsenal fans await the latest on Saka's problem, BBC Sport reports that the Gunners have concerns over the prognosis of Merino's recent foot injury.
The former Real Sociedad man was sent to see a specialist, and Arsenal will supposedly have a clearer picture on his injury within the next 48 hours, but they are preparing to be without him for a period of time.
The Gunners are reportedly concerned that Merino could be absent for a number of weeks with the potentially 'serious' issue, depriving Arteta of an experienced trophy winner at a critical point in the season.
The Euro 2024 champion has registered six goals and three assists in 33 games across all competitions this term, taking his total for the Gunners to 15 goals and eight assists since his arrival 18 months ago.
Which Arsenal games could Mikel Merino miss with foot injury?
The official length of Merino's absence has not yet been released, and neither Arsenal nor Arteta - who always keeps his cards close to his chest with team news - are likely to provide a timeline.
However, if the Spain international is indeed sidelined for 'a number of weeks', that suggests he will miss at least a month, including five fixtures in three competitions between now and the end of February.
Merino will firstly sit out Tuesday's EFL Cup second-leg clash with Chelsea, which is a significant boost for the Blues, as the midfielder has scored in each of his last two Premier League games against the Blues.
Clashes with Sunderland (February 7), Brentford (February 12), Wigan Athletic (February 15) and Tottenham Hotspur (February 22) should also come too soon for Merino, and it remains to be seen if he is fit for the next top-flight clash with Chelsea on March 1.
Merino and Saka are two of just three Arsenal fitness concerns at present, though, the other being Max Dowman, who is still working his way back from an ankle problem.