I think Mancini likes his midfielders (not attacking midfielders) to be stronger and more combative than Modric is as a solid defensive base is such an important part of Mancini's footballing philosophy to create a platform for the front four (and sometimes the full-backs) to run wild. That could be why we are linked with De Rossi, Martinez, and M'Vila (strong midfielders with good passing ability) rather than Modric or Sahin.