Guardiola's side host Everton on Boxing Day, before a trip to Leicester on December 29 and a home match against West Ham on January 4.
With all three rivals in the bottom seven, it presents City with an opportunity to improve on their recent horrendous record of four points from eight games, which Guardiola admits has left their lofty European ambitions in doubt.
He added: “The only team that participated in the Champions League in recent years is Manchester City.”
“Now we're in danger, of course we are. Absolutely.”
Arsenal, Chelsea, Liverpool and Manchester United finished in the top four of the Premier League from the 2005-06 to 2008-09 season. At least three of them also finished in the top four for 15 consecutive campaigns until 2012.
But United have spent five of the past 11 seasons outside the Champions League. Arsenal spent six seasons out of the competition before returning last season. Liverpool missed all but one year of the tournament in 2010, while Chelsea is in its second successive season outside the European elite.
This term threat to the city comes from unexpected sources. In addition to Forest and Bournemouth, Aston Villa is ahead of City, while Newcastle, Fulham and Brighton are also two points behind.
“There are a lot of competitors,” said Guardiola, whose team lost nine of the last 12 matches in all competitions. “For every club, this is very important, and if we don't win games, we are out.
“If we don't qualify, it's because we didn't deserve it, because we weren't prepared and because we faced a lot of problems and didn't solve them.”