The Blues defence may need revamping this summer as Marcos Alonso and Emerson Palmieri flatter to deceive, and Raphael Guerreiro could be the man to make the position his own.
Like most football people desperate for a hit of live action, Frank Lampard may well have watched Borussia Dortmund’s 4-0 Bundesliga victory over Schalke at the weekend.
And if he did, the Chelsea manager would surely have been impressed by several players in black and yellow, including Raphael Guerreiro.
The Dortmund left-back scored twice, putting to the sword a Schalke defence that just couldn’t cope with the drive and energy of his runs down the wing.
Full backs like Guerreiro are hard to come by, and the Blues could certainly use someone like him to round out their defensive line next season.
Lampard has made great progress in his first season as Chelsea boss. In doing so, the club legend has put his faith in academy graduates such as Tammy Abraham, Mason Mount, Fikayo Tomori and Billy Gilmour.
However, he lacks a young candidate to fill in at left-back where Chelsea only have a straight choice between Marcos Alonso and Emerson Palmieri.
Both players could be upgraded on, and finding a new left-back, along with a potent striker, appears to be a priority before next season.
Like so many modern full-backs, Guerreiro is a dominant force down the wing. He owns the entire flank when he is on the pitch, with Dortmund coach Lucien Favre willing to give him the freedom to truly influence matters.
That was evident in his performance against Schalke, when alongside Julian Brandt, Erling Haaland, Thorgan Hazard and Jadon Sancho, he would help overload the attack.
Guerreiro is a good dribbler – 1.4 per match in the Bundesliga this season, according to website WhoScored.com – and he is also Dortmund’s second most prolific crosser (0.8 per match).
Remarkably for a left-back, he also has seven league goals to his name for the season, so his display against Schalke was no fluke.
The goal threat Guerreiro carries is similar to that carried by Alonso at Chelsea.
For all the Spaniard’s defensive shortcomings, he remains a threat going forward, netting four times in just 11 Premier League appearances this season.
But Alonso usually struggles in a back four, so is often utilised as a wing-back in a back three. Guerreiro has no such problem. In fact, it’s a formation that gets the best out of the 26-year-old Portugal international.
His natural fitness and speed allows him to play as an auxiliary winger when Dortmund have the ball and as an orthodox full-back when they don’t.
At times, it’s as if Dortmund are playing with a back five, with Guerreiro and Achraf Hakimi both capable of pulling back to help out Mats Hummels, Manuel Akanji and Lukasz Piszczek in defence.
It is this sort of tactical flexibility that Lampard is missing at the back, with Chelsea’s defence often guilty of being too rigid this season.
Leicester City full-back Ben Chilwell has been linked with a move to Stamford Bridge, and he would also fit the bill for Lampard, but the England international wouldn’t come cheap.
Leicester demonstrated their resolve in the transfer market last summer by holding out for £80m from Manchester United for Harry Maguire.
They’d demand top dollar for Chilwell too, so Guerreiro may be a more realistic target as Lampard continues to shape his Chelsea side.
What’s more, he might actually be a better fit for the Blues. From putting their faith in youth to the way they play the game, parallels can be drawn between the team Dortmund are and the team Chelsea want to be. Guerreiro could help them bridge that gap.