McCarthy has endured an unhappy season to date, managing just four Premier League appearances under Koeman.
That is down in large part to persistent hamstring trouble but he has also found it difficult to dislodge a first-choice midfield pairing of Gareth Barry and Idrissa Gueye when fit.
Matters are complicated yet further by a simmering club versus country row between the Toffees and the Republic of Ireland, after he aggravated his injury on international duty and then withdrew from the next get-together
At present, the 26-year-old seems to be finding it hard to please any of his masters
When asked to comment on reports that McCarthy is looking for a fresh start, the Dutchman said only: "I don't know
I did not speak with James about his situation.
"For a long time he wasn't available for the team
Even last week he had only two training sessions and this week..
yes, he did train and is available for the weekend.
"About the future of James, the future of other players, new players..
that is not the focus I need to show at this moment."
Koeman was more forthcoming about his recent social media faux-pas.
He posted an innocent festive snap of his Christmas tree on Twitter only to be reminded in clear terms by Toffees fans that his choice of red decorations was not wise given the club's rivalry with Liverpool.
He quickly posted a second picture of a tree dressed in white and used his weekly press conference to identify the real culprit.
"This was a big mistake of my wife, put her under pressure!" he laughed, before reasserting his allegiances for the record.
"I understand the fanatic blue people
Of course I am the Everton manager, I'm a blue and will do everything to be successful at this great club.
"But I like a glass of red wine..
I don't need, if I drink a glass of red wine, to mention and to show I am a blue
But okay, it's funny
Don't take it too seriously."
Koeman's side have won only one of their last eight matches but also boast an unbeaten league record at Goodison Park.
Manchester United are their visitors on Sunday, when a home win would see Everton leapfrog the Red Devils into sixth place.
Source : PA