Mendy continues to struggle after undergoing knee surgery in November, despite making his comeback in the recent win at Burton Albion in the Carabao Cup.
And Kompany is yet to recover from the muscle problem he picked up in the win over Liverpool at the tun of the year.
Asked if either would be foot for the weekend, Guardiola said: “No.
“Mendy is injured and it's not easy. Meniscus. It is not easy. He needs to re-adapt.
“You can’t return and train for two days and you are fit. You have to be careful.”
Meanwhile, Guardiola says he has been impressed with Maurizio Sarri's impact since taking the reins at Chelsea in the summer.
The West London side have been in patchy form in 2019, but they remain involved in four competitions.
Guardiola, who praised Sarri's work at Napoli when City met the Italian side in the Champions League last season, says he could see a different Chelsea as far back as August in the Community Shield.
"People believed managers arrive at good clubs and immediately create something," he said.
"My feeling when I saw Chelsea at Community Shield was they were already there.
"They have been exceptional. Final of Carabao Cup, in Europa League, and Premier League they are there.
"They are nine behind with one less game and in the FA Cup they are there as well.
"I see them play and I recognise exactly what they want to do."