The Red Devils have been the Premier League’s top performing team in the opening games of the new campaign, with Manchester United only having dropped their first points against Stoke last weekend.
Manchester United are currently top of the table on goal difference and they also got their Champions League campaign off to a flying start by beating Basel 3-0 at Old Trafford on Tuesday night.
Mourinho brought in Victor Lindelof, Romelu Lukaku and Nemanja Matic during the summer transfer window ahead of his second season in charge.
And former Liverpool captain believes that Mourinho’s transfer business has been the main reason why the Red Devils look so strong this term.
Speaking on BT Sport on Tuesday night, Gerrard said: “Manchester United fans should be excited.
“Jose’s strengthened right through the spine and he’s also brought players right into form. Like Martial and Mkhitaryan.
“But the back-up defenders are not good enough against the big sides.”
Manchester United return to Premier League action on Sunday afternoon with a crunch clash against Everton at Old Trafford.
The Red Devils have only conceded two Premier League goals this term and have already netted 12 in their opening four games.
Manchester United finished in sixth place and won both the EFL Cup and Europa League last season under Mourinho.
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