Andre Villas-Boas all but conceded the Barclays Premier League title after watching Chelsea drop another two points in Monday's west London derby against Fulham.
After beating leaders Manchester City two weeks ago to haul themselves back into the title race, Chelsea completed a hat-trick of 1-1 draws to leave them 11 points off the pace following City's draw with West Brom and Manchester United's win against Wigan.
Anticipating another victory for Roberto Mancini's men, Villas-Boas said: "There's no big drama in terms of how we look at things. But you have to be sufficiently real. The difference between us and the top will be big. We had reduced it to seven points recently, but 13 points would be new for us."
He added: "With City and United continuing to get the points they are getting at the moment, it'll be difficult. That is the perspective we have to make at the moment: it's difficult. It's not impossible. You cannot say that.
"But we have to focus on our position at the moment and make a real assessment. Maybe the Premier League is over for us at the moment."
Fulham boss Martin Jol admitted gambling on his team selection after strikers Bobby Zamora (Achilles) and Andy Johnson (groin) both pulled out injured.
"Sometimes you have to take a gamble, and that is what we did today," he said. "Our two main strikers dropped out so we had to come up with something else. I think it paid off."
Indeed, Fulham were unrecognisable from Wednesday night's 5-0 home thrashing by Manchester United.
Jol added: "We had a good result against Liverpool, a good result at the Emirates. You can't say we are inconsistent - it was just against United that we didn't have a good result.
"We've shown we can give all these teams a good game."