Ghana midfielder Sulley Muntari joined Serie A champions AC Milan on loan from city rivals Inter Milan on Tuesday, the latest in a spate of transfers between the two clubs.
Milan said in a statement on transfer deadline day that the 27-year-old had arrived until the end of the season.
Muntari has struggled to hold down a first-team place at Inter, infuriating fans with some displays, and was loaned to Sunderland last term but again failed to make an impression.
Inter have replaced him with Porto's Colombia midfielder Fredy Guarin but coach Claudio Ranieri told the Inter TV channel it will take some time for the new recruit to reach full fitness.
Media reports have also said Inter are close to letting Thiago Motta join Paris St Germain despite denials from the Nerazzurri and are poised to replace the midfielder with Sampdoria's Angelo Palombo.