So far this season the Irish right-back hasn't been the relentless and industrious force that Everton fans fell in love with once upon a time.
The 30-year-old, recalled to the Toffees' first XI for Sunday's 2-0 win over Bournemouth after being benched by Marco Silva in the previous two matches, has been slated by the Goodison Park faithful in recent weeks.
They reacted very badly to his performance in the 1-0 defeat at Brighton on December 29 - and prior to that in the 6-2 demolition by Tottenham days previous.
It was a confidence-sapping festive period for Coleman - who suffered a double leg break on international duty almost two years ago - but new Boys in Green boss McCarthy is adamant that he can rely on his player despite his woes at club level.
"I’ve no worries about him at all. He’s such a good player, such a great lad and there is no problem," he told The Irish Examiner.
"Even if he wasn’t playing, I’d have no worries about him. I remember being in that situation at Millwall and not playing. Big Jack picked me every time I turned up. Because he could rely on me. I know I can rely on Seamus.
“Seamus has been a super player and he still is. Seamus is the captain and, if he’s fit, I’ve got total faith in him. My captain? Why not? I don’t see any reason why he wouldn’t to be.”
The brief stint out of Everton's first XI seemed to help Coleman, who had his best game for a while in yesterday's win over Eddie Howe's side at Goodison, despite a shaky start.
As the old adage goes, form is temporary and class is permanent and fans of the Merseyside club will be hoping this rings true in the coming weeks and months.