McCarthy wants to make the 22-year-old his sixth signing of the summer after he spent last season on loan at Molineux.
But Chelsea are keeping Wolves waiting over whether they are prepared to let Mancienne go - either permanently or for another loan period.
And McCarthy is concerned that he may miss out on other potential targets and is already being linked with St Etienne midfielder Guirane N'Daw.
McCarthy, who has been working as a BBC pundit at the World Cup, said: "I've been asked about Michael Mancienne, but we've done business and signed a centre-half in Steven Mouyokolo.
"I can't hang around waiting for decisions to be made that might be negative ones.
"I could lose the ones that I've been looking at so I don't know what will happen with that one (Mancienne).
"There might be more signings and we're still looking."
Mancienne had an initial loan period at Wolves when helping them gain promotion from the Championship 14 months ago.
He was brought in as a central defender but the form of Jody Craddock and Christophe Berra meant he was then employed in the holding midfield role during the second half of last season.