Kevin de Bruyne and Benjamin Mendy were not spotted in Manchester City training on Sunday ahead of the Manchester derby on Wednesday.
De Bruyne suffered a suspected muscular injury in City's weekend win over Tottenham at the Etihad, and was substituted in the 38th minute.
Manager Pep Guardiola said after the game he was a doubt for the clash with Manchester United, and would be assessed on Sunday.
“I don’t know how big an impact but I think the next games he will be out," Guardiola said. "I didn’t speak to him, but he put his hands on his hamstring. Tomorrow maybe we will know.”
But De Bruyne was not seen with the rest of the City squad in a training video published by the club on Sunday.
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Mendy was also a noticeable absentee from the video, having been left out of the matchday squad to face Spurs. The Frenchman had started three of City's previous four games after returning from a long-term injury lay-off, as City were managing his return to action.
It is worth noting that the pair were simply not shown on the video, and could have joined the squad later or worked separately.
Those players who started against Tottenham were shown taking part in a light training session, while the rest of the squad plus those who only came on as substitute, were seen enjoying a more high-tempo morning.
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City training squad ahead of Manchester United fixture:
Ederson, Muric, Bravo, Grimshaw
Danilo, Kompany, Otamendi, Laporte, Stones, Mangala, Walker, Delph, Zinchenko
Fernandinho, Gundogan, Foden, David Silva, Bernardo Silva,
Sterling, Sane, Poveda, Mahrez, Jesus, Aguero
Not seen - De Bruyne, Mendy
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