Ten Hag brought in former striker McCarthy as a first-team coach in the summer to help improve the standard of ‘positioning and attacking’ within the team.
The 44-year-old South African played for Blackburn Rovers and West Ham in the Premier League, spending five years in England from 2006 until 2011.
McCarthy also played for Ajax, where he won the Eredivisie, as well as for Celta Vigo in the Spanish top-flight.
It was at Porto where he enjoyed the most success, winning two Portuguese top-flight titles as well as lifting the Champions League under Jose Mourinho.
McCarthy scored 31 goals in 79 games for South Africa, and was crowned African Cup of Nations Best Player and won the Golden Boot at the 1998 tournament.
‘He’s definitely helped me a lot,’ Rashford said of his relationship with McCarthy.
‘To have them attack-minded coaches is good for us in the squad, he’s always there speaking to us about these things.’
Since retirement McCarthy has ventured into both coaching and first-team management, with his first job coming at Scottish club Hibernian where he joined the coaching staff under Alan Stubbs.
He then became assistant manager at Belgian club Sint-Truiden before a spell as a first-team boss for South African sides Cape Town City and AmaZulu.
McCarthy left AmaZulu in March and joined United as first-team coach in the summer.
‘There was still one place in our coaching staff that I wanted to fill,’ Ten Hag told United’s website when explaining his decision to bring McCarthy to Old Trafford.
‘He has experience as a manager. He was a coach in the professional level and he was a former striker, a really successful striker as well.
‘He will focus on the positioning and attacking. I’m not saying only the strikers, but also the integration from the full-backs and midfielders. Our way of play has to be dynamic.’
United return to action on Sunday with a trip to west London to face Fulham.
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