Former Chelsea captain Marcel Desailly believes the Premier League champions must sign either Edinson Cavani or Gonzalo Higuain to replace Didier Drogba this summer.
The Ivorian is expected to leave Stamford Bridge this summer, a year on from re-joining the club for a second spell.
Although Diego Costa will likely finish the season as the club's top scorer with 19 goals, the Spaniard has spent regular spells out of the Chelsea team due to injury.
And Desailly feels the 26-year-old needs genuine support next season and only Paris Saint Germain forward Cavani, who could be available for £50m, or Napoli hitman Higuain, who is valued at £29m, are capable of filling the void.
"Chelsea needs another striker," the French World Cup winner told Goal.com. "Costa has done well, Drogba also, but they need a third top player.
"A Cavani, a Higuain, someone very close to Costa [in ability] to be able to think about winning a Champions League. In other areas I don't see anything unless a player leaves."
Aside from Chelsea's pursuit of a forward, Desailly feels the central narrative of the upcoming transfer window will centre around Paul Pogba.
Pogba has been heavily linked with a move away from Champions League finalists Juventus and Desailly believes Real Madrid represent the most realistic destination for the France international, ahead of Manchester City.
"Juventus are in the final of the Champions League, they won Serie A," he added. "Why would he want to move from there unless crazy club comes in with big money?
"City, I think, would be just for the money. Madrid would be for the prestige. Madrid is probably the best club for him, where the philosophy is to play forward.
"If they play three in midfield Madrid could be tactically the best team for him to express himself. He would be an amazing player.
"But if he leaves Juventus, Madrid is the best club for him. If you leave Juventus -- I know Serie A is not the best league but it is a prestigious club - you need to go to Real Madrid."