Former Chelsea defender William Gallas has warned Chelsea striker Nicolas Jackson that he needs to become a more ruthless goalscorer or risk losing his place in the starting XI to Christopher Nkunku.

Jackson has four goals and three assists after seven Premier League games while Nkunku has seven goals across all competitions this campaign.

“Enzo Maresca knows what he is doing with Christopher Nkunku and Nicolas Jackson, he has them in competition with each other so they know they have to be at their very best to stay in the team,” Gallas told Prime Casino.

“They both want to start and they’ve both been showing that they can score goals, if one of them stops scoring then the other one will play.

“I think Jackson should be targeting 20 goals this season after getting 14 last year, he needs to keep improving because he knows he is in competition with Nkunku.

“Jackson has improved but he needs to do better, if he gets three or four good chances he needs to be scoring at least two of them. At the moment he needs five chances for every goal.”