Following an impressive 4-1 victory over fourth-placed Aston Villa, just a point covers the top three although Liverpool play on Thursday night.
With just eight games remaining, it looks set to be a close finish going right to the last game on May 19.
“If we win all our games it will be down to the last day because they are not five, six, seven points in front,” Guardiola said.
“It will not be easy. I see Liverpool and Arsenal dropping points but you never know.
“We have to show up and do our job and don’t regret that we should have won that game because they lost the game after.
“We cannot do anything. We cannot control what they do. We have to win our games, that’s all we can do.”
With little room for dropped points, Villa presented another tough test following games against the other top-four sides Liverpool and Arsenal.
After Jhon Duran pulled the visitors level following Rodrigo’s opener, Phil Foden scored a brilliant hat-trick to secure all three points.
His first came just before half-time from a free-kick, before an instinctive strike was followed by unstoppable hit into the top corner giving goalkeeper Robin Olsen no chance.
Foden now has 21 goals for the season on top of 10 assists and Guardiola praised the way he comes alive around the box.
“What can I say, he scored three goals?” he said.
“He didn’t start well. The goal helped him a lot for the mood in the second half.
“When he plays in a central position he has a sense of goal.
“Everyone has their own skills and talents and Phil has assists and goals in that position. He proved it again.”
Foden is an outstanding season and Guardiola added that he is still getting better all the time.
“He can do whatever he wants,” the boss said. “He’s a really top class player.
“He is open minded. He has to understand the game. He has to focus in some things.
“Sometimes he is a little bit distracted in what he has to do defensively but he has a natural talent. A gift.
“He is special for the pace and work ethic. He has an incredible sense of goal.
“You have the feeling when he is attacking the last line that he is going to score.
“It’s not easy to find it and that’s why he is so special in those central positions.”
