Chelsea are closing in on a club record deal for goalkeeper Kepa as Thibaut Courtois looks set to join Real Madrid.
But Neville thinks Chelsea need at least one more player and to keep their star man to have any chance.
"To win the league they have to keep Hazard and they're going to have to get a centre forward," told Sky Sports' Premier League launch show.
"Morata's a good player but for me you think about the void of Costa, if they're going to play a single striker which Chelsea historically have, for me they need another striker."
Chelsea finished fifth last year and Antonio Conte was dismissed at the start of pre-season to be replaced by Maurizio Sarri.

He is set to lose his goalkeeper who will join Real Madrid before the end of the month with Kepa coming in to replace him.
Chelsea have triggered Kepa's release clause but Neville has warned him about coming to Chelsea.
"For me, Courtois is one of the best," the former Man Utd captain added.








"I absolutely love him. I know people say I’m critical of 'keepers, but I also love quite a few keepers and I absolutely love Courtois.
"He’s [Kepa] got big shoes to fill and it’s a big price. Pep Guardiola said in an interview with us that Chelsea are going to do quite a lot of business in the next few days and obviously the market talks and agents talk.
"Chelsea look like they are moving. They have been a little slow in the transfer market and a little bit less obvious in the transfer market over the last few years than they have been previously. It looks like they are making a move again."









Chelsea are closing in on a club record deal for goalkeeper Kepa as Thibaut Courtois looks set to join Real Madrid.
But Neville thinks Chelsea need at least one more player and to keep their star man to have any chance.
"To win the league they have to keep Hazard and they're going to have to get a centre forward," told Sky Sports' Premier League launch show.
"Morata's a good player but for me you think about the void of Costa, if they're going to play a single striker which Chelsea historically have, for me they need another striker."
Chelsea finished fifth last year and Antonio Conte was dismissed at the start of pre-season to be replaced by Maurizio Sarri.

He is set to lose his goalkeeper who will join Real Madrid before the end of the month with Kepa coming in to replace him.
Chelsea have triggered Kepa's release clause but Neville has warned him about coming to Chelsea.
"For me, Courtois is one of the best," the former Man Utd captain added.








"I absolutely love him. I know people say I’m critical of 'keepers, but I also love quite a few keepers and I absolutely love Courtois.
"He’s [Kepa] got big shoes to fill and it’s a big price. Pep Guardiola said in an interview with us that Chelsea are going to do quite a lot of business in the next few days and obviously the market talks and agents talk.
"Chelsea look like they are moving. They have been a little slow in the transfer market and a little bit less obvious in the transfer market over the last few years than they have been previously. It looks like they are making a move again."