The Blues are already locked in negotiations with the Serie A side over a deal to sign the Colombia midfielder. However, the two clubs are still yet to agree a fee, with Inter unwilling to lower their £16.5m valuation of the former Porto man. Ba, who has scored only three league goals since his January switch to Stamford Bridge, is reportedly expendable at west London and Chelsea are willing to offer the Senegal striker and cash to the San Siro club in return for Guarin. But despite Inter’s need for attacking reinforcements, Calciomercatonews claim Inter boss Walter Mazzarri is unsure of Ba’s suitability for his side.