Former Chelsea defender Wayne Bridge has claimed that the Blues need to sign a new forward during the January transfer window.
However, Bridge has suggested that Chelsea require a forward who can "bully defenders" like Costa and club legend Didier Drogba.
At the Pokerstars Festival in Dublin, the 37-year-old said: "Morata has obvious quality - he's quick, he's running in behind and scoring goals with his head and his feet.
"He's a totally different player in terms of what Chelsea are used to, with the likes of Didier Drogba and Costa who are big and strong and bullied defenders. With the likes of Fabregas who can slip him in, with the runs that he makes he's going to get chances.
"I really like him but I expect them to probably sign another centre-forward in January. Not to replace Morata but someone either to work with him or they can change. Someone physically a bit stronger and who wants to bully defenders."
Between 2003 and 2009, Bridge made a total of 142 appearances for Chelsea in all competitions.