Kevin De Bruyne picked up a muscle injury as he limped off the field in Manchester City's 2-0 victory over Aston Villa at the Etihad.
The Belgian, who had bagged one goal and three assists in his previous three games heading into the clash with Villa, was caught by a late challenge from Jack Grealish shortly after the start of the second half and managed just five more minutes before being withdrawn.
After the match, Guardiola answered questions about De Bruyne's fitness, but the boss confessed at the time that he wouldn't know much until the results of scans on the midfielder had come back.
“I haven’t spoken to the doctor,” he revealed (via the club's official website). “Kevin put his hand on his leg, so I have the feeling it will be something muscular. “It is normal, these things happen with this amount of games.”
A report from the Mirror then suggested that De Bruyne was likely to miss around two or three weeks of action with a small hamstring tear, but Guardiola has confirmed the problem is worse than first feared.
"Kevin, like the doctor said today after reviewing the scan, will be 4-6 weeks out," Guardiola said (via MEN). "It's a big blow, isn't it. It is but we have to move forward. I'm not saying anything that anyone doesn't know, it is unfortunate for him and for us and we have to find a solution because everyone in their own life is struggling in the situation we are living and we have to adapt."
If that timeline is accurate, De Bruyne will be missing for a number of crucial games for City - including Premier League clashes with Liverpool, Tottenham and Arsenal, potentially the first leg of the Champions League round of 16 clash with Monchengladbach and the Manchester derby.
What games could De Bruyne miss?
Cheltenham (A) - (FA Cup fourth round) - 23/01
West Brom (A) - (Premier League) - 26/01
Sheff Utd (H) - (Premier League) - 30/01
Burnley (A) - (Premier League) - 03/02
Liverpool (A) - (Premier League) - 07/02
Tottenham (H) - (Premier League) - 13/02
Arsenal (A) - (Premier League) - 21/02
Mönchengladbach (A) - (Champions League round of 16) - 24/02
West Ham (H) - (Premier League) - 27/02
Man Utd (H) - (Premier League) - 06/03
With Sergio Aguero still in isolation following a positive COVID-19 test, Guardiola opted to deploy Bernardo Silva as a false nine against Villa; but the Portuguese international could return to midfield with De Bruyne on the sidelines.
It's not only Guardiola who will be scratching his head over De Bruyne's absence. The City midfielder is one of the most popular choices in fantasy football, and finding somebody to fill the void he leaves is easier said than done.
Fortunately, if you do need to replace De Bruyne, you'll likely have a near-unlimited selection of replacements because of the Belgian's high price tag. Bruno Fernandes, Son Heung-min and Grealish are all high-achieving alternatives, while cheaper options like Marcus Rashford, Wilfried Zaha and even Pedro Neto are all worth considering.
De Bruyne wasn't the only man felled by Grealish against Villa as right-back Kyle Walker was forced off earlier in the game after a tough challenge from his England team-mate. His knock isn't so bad, fortunately.