"We are five points in front of Manchester United... (with) 84 points to play for. It's nothing," the Spaniard told a news conference on Friday.
"If we play until May the way we have the last two months, I think 'wow we have a good chance to win the Premier League'.
"Who will assure me that is going to happen? Who will assure me we won't have injured players? Who's going to assure me we won't have bad moments... It is impossible to maintain what we have done in the past two months."
Guardiola, who guided City to a 4-2 win at Napoli in the Champions League in midweek, acknowledged the threat that Arsene Wenger's men posed to his team as they look to go into next week's international break with a win.
"Arsenal are one of the best opponents for my team. They have won a lot of games. Against Arsenal it is always complicated," Guardiola said.
"It is the last game before the international break and hopefully we can recover well from Napoli and put on a good performance in front of our fans and win the game."
Arsenal, who are fifth in the league with 19 points, have lost only once to City in their last nine meetings in all competitions winning four and drawing four.
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Christian Radnedge)
