Kevin De Bruyne has suffered a fresh injury setback in a major blow to Manchester City.
The Belgian only recently returned from a hamstring problem that he picked up just 23 minutes into the opening game of the season at Burnley.
De Bruyne underwent surgery and missed five months of action, before he made his comeback off the bench in an FA Cup tie against Huddersfield on January 7.
The 32-year-old has excelled since returning to fitness, making eight appearances in all competitions, but he remained an unused substitute during City's 1-0 win over Brentford on Tuesday.
And, speaking after the game, Pep Guardiola confirmed De Bruyne didn't play against the Bees because he is dealing with a fresh hamstring issue.
Kevin De Bruyne has suffered a fresh injury setback in a major blow to Manchester City
De Bruyne remained an unused substitute throughout City's 1-0 win over Brentford on Tuesday
'We did not use Kevin today because he has niggles in his hamstring position,' the Spaniard said.
'He's okay. It's more caution and prevention than anything. He didn't feel comfortable and the doctors said there was a little bit of risk.
'After five months off, we did not take any risk with that.'
De Bruyne started and played the full 90 minutes of City's 1-1 draw with Chelsea on Saturday, but was dropped to the bench for the game against Brentford.
However, he did not emerge before the game to warm-up with the other substitutes, while he never went out during the match either and remained on the bench throughout.
Guardiola has recently discussed the need to manage players that are returning from injury, with De Bruyne - who also suffered a hamstring injury in the Champions League final in June - having admitted he doesn't yet feel back in top shape.
City boss Pep Guardiola revealed the playmaker is struggling with 'niggles in his hamstring'
De Bruyne only recently returned from a five month absence after he picked up a hamstring injury in the first game of the Premier League season against Burnley back in August
De Bruyne's setback comes amid a hectic and crunch run of fixtures for City as they continue to compete on three fronts.
Over the next two-and-a-half weeks, they face Premier League games against Bournemouth, Man United and Liverpool, while they also take on Luton in the FA Cup and FC Copenhagen in the second leg of their Champions League last-16 tie.
John Stones and Bernardo Silva returned to the starting line-up against Brentford after recent injuries, but Josko Gvardiol and Jack Grealish remain out.