"Maybe this season finally you demand that they win," Mourinho said when asked about Liverpool's spending after United's International Champions Cup win over AC Milan.
"I can't see anyone else getting close to spending what they have [this summer]," he added. "A team that was a finalist in the Champions League, you have to say you are a big candidate, you have to win."
Brazilian goalkeeper Alisson (£67m) became Liverpool's fourth signing of the summer last week following the arrivals of Naby Keita (£53.75m), Fabinho (£43m) and Xherdan Shaqiri (£13.5m), taking Liverpool's summer spending to £176.95m.
It's more than any other Premier League side have spent this summer - and more than double as much as United, who have so far spent £53m on Fred, £19m on Diogo Dalot and £1.5m on Lee Grant. Mourinho does, however, hope to make two more signings before the window closes.
Any new signings will see United close the spending gap on Liverpool for this summer, but how do the two sides compare since Mourinho's appointment at United in May 2016?
Liverpool v Man Utd: Transfer spending comparison since summer 2016
|Team||Total spend||Fees received||Total net spend|
As things stand, Liverpool have spent more, with Alisson's arrival taking their overall spend since the summer of 2016 to £411.55m, compared to United's £392.55. Remember, they did not pay transfer fees for Alexis Sanchez or Zlatan Ibrahimovic.
Liverpool's most expensive signing in that timeframe is Virgil van Dijk, who cost £75m from Southampton, while United's is Paul Pogba, whose move from Juventus was worth £93.25m.
United are likely to surpass Liverpool's total if Mourinho gets the two additional signings he wants before this summer's deadline, which would extend their net spend, too.
Liverpool v Man Utd: Highest transfer fees paid since summer 2016
|Paul Pogba||Man Utd||£93.25m|
|Romelu Lukaku||Man Utd||£90m|
|Virgil van Dijk||Liverpool||£75m|
United have only received £85.3m in player sales since Mourinho's appointment, with Memphis Depay the most lucrative at £21.7m, but Liverpool have received £289.65m - a total which includes the £146m fee from Barcelona for Philippe Coutinho.
So, while Mourinho's United are likely to remain bigger spenders than Klopp's Liverpool by the end of the transfer window, the Portuguese has a point when he suggests expectations on the Reds should be cranked up.
Both on and off the pitch, the famous rivalry promises more fireworks in the season ahead.
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