The winger was left out of the Manchester United matchday squad on Sunday by Ruben Amorim.
Rashford joined Alejandro Garnacho in being axed for the trip to the Etihad Stadium.
Explaining his decision, Amorim said ahead of the match: "For me it's important; the performance in training, the performance in games, the way you dress, the way you eat, the way you engage with your team-mates, the way you push your team-mates."
Meanwhile, the 27-year-old cheered on his team-mates as he watched the match at home.
Following United's dramatic late turnaround, Rashford shared a snap of the match on his TV to Instagram.
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In the caption, he wrote: "Yesssssssss! Love it lads."
His brother and agent Dwaine Maynard also gave his reaction in the comments section.
Maynard added: "As you say, all you want is United to win. Regardless of anything else."
Rashford's absence on Sunday has been followed by reports he has been put up for sale by the Red Devils.
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According to The Guardian, the decision is part of a cultural reboot at Old Trafford.
It is seen as necessary to transform the club's fortunes after a decline in standards over the last decade, the report adds.
Rashford still has over three years remaining on his current contract, though.
The academy graduate penned a new deal through to 2028 last summer.
So far this season, he has scored seven goals and provided three assists in 24 appearances across all competitions.
Those include three strikes in his six matches since Amorim's arrival.
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