It is, but again, who? Who is there who would really improve us and who would be available as well for the CL?
Why do we need someone who's eligible for CL? We will be better off with someone who could help us in the league only than no one at all, certainly? I don't get all this talk about players having not to be cup-tied to be bought by us.
There are plenty of midfielders who would improve us. If you want someone who will be free to play in CL, then you have M'Vila, Martinez and Rodwell for the defensive work. If you want creativity then most of available ones are indeed cup-tied for CL - Eriksen, Hazard and Gotze.