McCarthy is unsurprised by the interest in Fletcher, who has netted against Liverpool, Manchester United, Arsenal and Tottenham this season. But he is hoping Wolves can progress and become the sort of club who do not lose their major players if the elite teams show an interest.
McCarthy said: "Fletch is having a great season and he is a terrific player. He puts in a great shift and scores goals in a team which doesn't create as many chances as some others. Of course, he will attract interest from other clubs. I would expect that. I think he's capable of playing anywhere, personally."
He added: "Everyone wants me to say 'he's not for sale' but, come on, why would we be interested when we've got our own problems.
"There haven't been any offers for him and I think there are certain things that, unless you're dead keen on doing it as a manager, you don't do."
McCarthy added: "It doesn't irritate me to get asked if leading players are for sale. That's the way it is. It's part of the gig.
"What irritates me is how the story gets twisted into 'McCarthy denies any interest' or says 'he's not for sale.' The story becomes something it's not.
"We're trying to ensure we progress to being the team that means players don't want to leave.
"But, let me tell you, there are a lot of people who would be delighted to be here."
Fletcher is set to return to the side for Saturday's home derby with Aston Villa after being rested for Wednesday night's FA Cup third-round replay loss to Birmingham.