Jose Mourinho has always been a big spender in the transfer market - not just since he arrived at Manchester United.

The Portuguese tactician signed roughly £555 million worth of players for Porto, Chelsea, Inter and Real Madrid, but he really kicked it up a gear when he took over at Old Trafford.

At the expense of £450 million, Mourinho has overseen the arrival of ten players during his two-and-a-half seasons as United boss.

With Paul Pogba (£94 million), Romelu Lukaku (£76 million) and Fred (£53 million) all bought on his watch, he unsurprisingly tops the list of total career expenditure by a manager at £1.04 billion.

Pep Guardiola is only £10 million or so adrift in terms of overall spending, but his activity at Manchester City tells a different story.

The Sky Blues have invested more than £535 million in new signings since the 41-year-old took charge - a figure that’s given Mourinho some handy ammunition ahead of Sunday’s Manchester derby.

Honing in on the acquisitions of Kyle Walker, Aymeric Laporte, Danilo and Benjamin Mendy, he couldn’t resist having a dig at City’s tendency to buy solutions rather than find them through clever management.

“If I need a full-back and I buy four, it is easier,” Mourinho said, per the Sun.

“If I need a full-back because I am not happy with Luke Shaw’s level, the easiest thing is to buy four. Some clubs can buy four.

“We didn’t buy a left-back for three years, we were wishing and working with Luke to be that left-back.

“But during that process we played Matteo Darmian, we played Ashley Young, we played Marcos Rojo. We didn’t buy four.

“There is a difference. To buy four you only need good scouting and money - to make players takes more time."

MOURINHO TAKES AIM AT SERGIO AGUERO

Eager to set the tone for the Red Devils’ trip to the Etihad, Mourinho didn’t stop there.

His second pop singled out Sergio Aguero - who was caught up in an apparent head-butting incident that saw Marouane Fellaini sent off when United played City in April last year.

After watching Aguero throw himself to the pitch in agony during his confrontation with the Belgian, Mourinho claimed he later saw the striker in the tunnel with “no broken nose, no broken head, his face is nice as always... it was a bit red card and a bit experienced, smart Argentinian player.”

Despite his venomous words, Mourinho insists he is still a fan of Aguero for his footballing prowess alone.

“I admire him because of his fantastic qualities but there are little things in his game that I am not a big fan.”

When asked to elaborate, though, his response was unusually reserved, saying: “I keep for me.”

You can never predict what you’re going to get with Mourinho in a big match, but if his antics leading up to this Manchester derby suggest anything, he could be in the mood for some fireworks.