The 24-year-old has been named Premier League Player of the Month for August after scoring seven goals in City's opening three matches against Chelsea, Ipswich Town and West Ham United.
After netting in the Citizens' 2-0 opening-weekend win at Chelsea, Haaland scored back-to-back hat-tricks in 4-1 and 3-1 victories over Ipswich and West Ham respectively, before scoring on international duty for Norway in a 2-1 win over Austria in the UEFA Nations League on Monday.
Haaland has since returned to Man City training unscathed, but the striker has emerged as a doubt for Saturday's contest as he is mourning the loss of close family friend Ivar Eggja, who passed away aged 59 earlier this week.
Eggja, who was Alf-Inge Haaland's best man at his wedding, was known as an 'uncle' to Erling and found apartments for the striker during his time at Red Bull Salzburg, Borussia Dortmund and Man City. He also accompanied him to last year's Ballon d'Or awards.
In the run-up to Saturday's encounter with Brentford, Haaland will be given time to comes to terms with the bereavement of Eggja, with Guardiola offering his condolences to the striker during this difficult time.
Speaking at a pre-match press conference on Friday, Guardiola told reporters: "It is a tough moment for him and his family.
"It was sad news. He was close to him and his family. 59 years old. Our thoughts are with him and his family.
"We will see tomorrow if he is mentally and physically able to play."
Who could replace Haaland for Brentford clash?
Haaland has trained with Man City since returning from international duty with Norway and there is still a good chance that he could feature on Saturday.
However, should he be absent, Guardiola must make a decision on who will lead the line, with no other recognised centre-forward in his senior squad - City are a man light in this department following the departure of Julian Alvarez to Atletico Madrid and the injury sustained by Oscar Bobb.
Guardiola would be forced to revert to using a false-nine if Haaland is indeed unavailable for selection, with the likes of Phil Foden, Kevin De Bruyne and Bernardo Silva all capable of operating in the central role.
Meanwhile, Guardiola has revealed that both Foden and Rodri are available for selection after taking part in training this week, while ha has also confirmed the extend of Nathan Ake's injury picked up on international duty with the Netherlands.