Former Manchester United defender Gary Neville thinks that Sunday is the most important day in the title race so far and thinks the Red Devils' game against Tottenham could decide where the title goes.
United are now five points behind rivals City - who beat Bolton 2-0 on Saturday - and while they have not lost to Spurs in a decade, Neville believes any slip-up against Harry Redknapp's high-flying side would be critical.
"Today [Sunday] is the most significant day in the Premier League title race up to now," he wrote in the Daily Mail. "I know everyone, including Sir Alex Ferguson and Roberto Mancini, is talking about the potential title shoot-out, when Manchester United travel to play Manchester City on April 30, as title D-Day. That may be the case but my gut feeling is that D-Day comes today and April 30 will be Coronation Day."
Neville also looked at the fact that United's remaining matches this season are far easier than City's.
"Though both clubs will be approaching each match as it comes, they will have taken a look ahead and know the fixtures now dramatically turn in United's favour. United's run-in, other than that game at City, is as gentle as could be expected in the Premier League," he added.
"There are the obvious games against top sides that are dangerous and City have more of those, against Chelsea, Arsenal and United. But we used to say in the dressing room those games would take care of themselves. They are so clearly significant there never is any need to remind players to be motivated.
"But any away game is a potential hazard and matches at Norwich and Swansea, both of whom have passionate support, tight grounds, great home records and good managers with players in form, are dangers.
"We used to say in the dressing room: 'We have to be at it, today.' A match like Wolves away, against a side who are struggling but fighting for their lives, is one where, if you are 'at it', you'll win. But any complacency and you'll get a shock and be punished. And so City's run of away games at Swansea, Stoke, Norwich, Wolves and Newcastle is hazardous."
From City's perspective, Neville said they would be hoping that Spurs can end their poor run against United.
"City will be hoping to see a Tottenham side playing the way they have been for the majority of the season, rather than the side they saw in the 50 minutes against Arsenal last week. Because that Tottenham side - the good one - can cause United difficulties," he said.
"Against Tottenham will be the statistics. They haven't beaten United for 25 games and though their home record is good, United have the best away record in the top flight with an especially good record at White Hart Lane.
"Despite all that, given the way Tottenham have been playing, you have to say last Sunday was a blip. It was a real surprise to see them fall apart after leading 2-0. You could never have imagined that because Tottenham were unrecognisable from the side they have become: compact, hard to break down and resilient.
"For United, though, there is just as big an incentive. Win today and they can seize control of the title race and will believe they are a huge step closer to winning the league."