The fact Chelsea have managed to occupy a top-four spot for the majority of the season speaks volumes considering there is a major flaw in Frank Lampard's team.
Lampard has managed to revamp the Blues as an attacking, youthful outfit but the bedrock of their success over the years - their rock-solid defence - has been eroded.
The Blues have a brittle back line that has been exposed time and time again throughout the season. They have the worst goals against record in the top 10 - conceding more than Arsenal and Tottenham, who are both enduring wretched campaigns.
Saturday's 3-0 defeat to Sheffield United- which could prove costly in the race for Champions League qualification - underlined the need for defensive signings in the summer transfer window.
The Blades' second goal highlighted the need for a new central defender as Andreas Christensen and Kurt Zouma were caught ball watching as Oli McBurnie headed home Enda Stevens' cross. It also highlighted why Cesar Azpilicueta is needed at right-back instead of left-back as Reece James and Willian failed to track Stevens' run down the wing.
Before David McGoldrick and McBurnie netted, Azpilicueta demonstrated why a new left-back is needed.
A well-worked move found the Spaniard free on the wing but his left-footed cross went behind the goal and the potential for a goal was gone.
Lampard reacted to Chelsea's nightmare half by bringing on Marcos Alonso and Antonio Rudiger on at the break and switching to a back five - substitutions that spoke volumes.
Alonso is available for sale after failing to impress the club legend while Rudiger's form since the Premier League restart has been disappointing.
But the changes didn't have the desired effect as shambolic defending played a role in McGoldrick's second goal of the game.
It is an open secret that Lampard wants a new left-back, with Emerson Palmieri also set to be shown the door.
Express Sport understands Leicester City ace Ben Chilwell is the man Lampard fancies to fill the problem position.
The Foxes are in a strong financial position, however, and will drive a hard bargain similar to their £80million sale of Harry Maguire to Manchester United last summer.
Ajax ace Nicolas Tagliafico and Porto star Alex Telles are back-up targets.
A new centre-back has also been mooted. The current options at Lampard's disposal are decent but not title-winning quality.
A commanding presence capable of taking the game by the scruff of the neck is required.
The likes of Lille's ace Gabriel Magalhaes and Nathan Ake of Bournemouth have been linked.
Whether they are capable of being the answer remains to be seen but signing a central defender is a must.
Chelsea's ambitious approach to the summer transfer window and Marina Granovskaia's speed at getting deals done for Hakim Ziyech and Timo Werner has to be applauded.
Kai Havertz is also wanted but the Blues should really be fixing their defence before adding more to their attack.
After witnessing his team concede three times against Chris Wilder's team, Lampard must demand Granovskaia turns her attention to getting a left-back and a centre-back through the door.
Otherwise, they will continue to be undermined by their fragile defence.