McCarthy, 44, was confirmed as United's new first-team coach last month. The former South Africa international and Champions League winner has been coaching for nearly a decade, working at Hibernian before managerial roles in his homeland with Cape Town City and Amazulu.
The Daily Mail says McCarthy is a popular addition to United's coaching staff. The self-confessed Red Devils fan has been holding extra shooting practice sessions at the club's Carrington training ground after being asked by Bruno Fernandes.
It's believed these sessions have proved popular and various players - including Ronaldo and Cristian Eriksen - have joined in. Defender Lisandro Martinez has also got in on the fun. McCarthy once scored 18 Premier League goals in a single season at Blackburn.
But McCarthy's work is yet to make an impact on Ten Hag's side. United lost 2-1 at home to Brighton on Sunday afternoon, with Alexis Mac Allister's own goal going down as the first strike of the Ten Hag era.