"It's now not in our hands, before it was, now no," Guardiola said.
"Four games we have (remaining) in the Premier League. They will be quite similar and we'll see what happens."
City had the chance to draw level on points with leaders Arsenal with victories over Everton on Monday and Brentford five days later.
Instead, they find themselves five points adrift, albeit with a game in hand, and needing a wobble from Arsenal.
Guardiola was left to reflect on a point salvaged rather than three secured at Hill Dickinson Stadium.
"It's better than losing," he said. "We'd rather win. We play for that and we just showed what a team we are. We tried everything. The players were aggressive."
Winger Jeremy Doku struck the dramatic equaliser in the 97th minute to complete a double on the night, and echoed his manager's frustration while insisting City had not abandoned belief with four league games still to play.
"It's painful now but there's still a lot of games to go and anything can happen," Doku said. "We'll keep on fighting. We owe it to ourselves and our fans."
City striker Erling Haaland, who scored in the 83rd minute, could be heard saying "We're still in it" as he shook hands with his teammates after the final whistle.
Following Saturday's game against Brentford, City face Crystal Palace, Bournemouth and Aston Villa in their final three league games.
Arsenal have the far easier schedule, at least on paper, with games against relegation-threatened West Ham United, already-relegated Burnley and Palace.
While their hopes of winning the league suffered a huge blow on Monday, City are technically still in the running for a domestic treble. They beat Arsenal to win the League Cup in March, and meet Chelsea in the FA Cup final on May 16.