Everton manager Roberto Martinez suggested yesterday that the deal to sign Tom Cleverley on loan from Manchester United didn't go through because United were unwilling to let him go to a Premier League rival.
Last summer, it would have been thought inconceivable that the two would have considered the two as fierce competitors for positions in the Premier League - even with the departure of Sir Alex Ferguson, and David Moyes moving down the East Lancs Road to take the job at Old Trafford.
Nor would it have been thought conceivable that Everton will have finished eight points ahead of United last season in Roberto Martinez's first season at the helm on Merseyside.
But it happened - and both teams have the goal of trying to finish in the Champions League places this season. It would make sense that if United didn't want to help Everton's cause, then they're not going to lend them another player.
The Everton boss said: "You can look at the table from last season and we finished fifth and they finished a bit lower, so from that respect you can understand."
In the long term though, it may not be the case. Everton smashed their transfer record this summer in order to make the loan signing of Romelu Lukaku from Chelsea a permanent one at the cost of £28 million. But the gulf in financial muscle is vast, as is the amount they can afford in wages.
Manchester United have smashed the British record by spending close to £60 million to sign Angel Di Maria from Real Madrid, and spent in excess of £150 million in total. When you have a turnover in excess of £400 million, the money at your disposal can count for a lot.
In the short term, the two may be vying for league position. United's financial muscle is likely to contribute to them moving back towards the summit - so if Everton want to remain their rivals they're going to have to do one of two things. Spend a lot of money, or get into the Champions League within the next two seasons.
There will always be the rivalry between the two fans from as their from their two main cities in the North West, and they will want to get one over on each other. But Everton could find their rivalry in terms of close competitors with United short lived unless they find some kind of success in the near future - qualification for the Champions League for the Toffees could lead to the two side's being rivals for years to come if they can then build on it.