It's a big summer for after the club ultimately delivered on the pitch this season.
In what was a trying start to the campaign, came into the club and introduced his own style of play onto the team following departure last summer.
There have been plenty of transfers for the club since and Clearlake Capital bought the club from in 2022 - and after qualifying for the and winning the Conference League this year, there are sure to be some more this summer.
It already seems as though the Blues have got a deal for wrapped up after the Ipswich Town striker elected to join the Blues over a number of other clubs, with letting Ipswich know that they plan to activate his release clause when the transfer window opens.
However, there are still question marks throughout the squad, with unsettled goalkeepers this season, a potential new centre-back to consider and whether loan move from will be made permanent.
After the signing of Delap when the window opens, what will be the Blues' biggest priority? football.london writers give their opinion below...
Lee WilmotDelap to Chelsea is close to being finalised, so who comes next? It's hard to say with Chelsea.
Where do they really need strengthening apart from up front? My feeling is in goal, despite the fact the Blues have about 15 on the books at Stamford Bridge.
They needed added depth in the forward line and Delap brings that, but they also need a top-class goalkeeper to challenge at the top of the Premier League and in the Champions League next season. Robert Sanchez and Filip Jorgensen just are not up to it in my view.
Caoimhin Kelleher has been linked before and he's far too good to be a number two at Liverpool. Brentford are reportedly in the market to sign the Reds keeper, and that then opens up the option of Mark Flekken. Will he be happy at the Bees if Kelleher comes in?
Either way, both would be upgrades on what Chelsea have got.
Tom ColeyWith a striker through the door, the main position next is a winger. Chelsea are searching for a right-footed left-sided player. They do have Mykhailo Mudryk and Jadon Sancho but there is uncertainty over the short and long-term future for both.
Who is the player they need? Alejandro Garnacho and Jamie Gittens are the linked names but neither inspire full confidence.
Chelsea could have done with Khvicha Kvaratskhelia in January, really. The rest of the options are underwhelming. Nico Williams is too expensive and far from a definite to be worth the money given his levels of output.
Garnacho feels like the most likely given the previous interest and a reduced price after being shunted out at Manchester United. If it could be done for £40million then would it be the worst?
Joe DoyleThe Blues are in an interesting predicament. While there is quality throughout the squad, there's probably only three or four players who you would say are absolutely undroppable at the moment: Marc Cucurella, Enzo Fernandez, Moises Caicedo and Cole Palmer.
Levi Colwill is probably in with a shout too - though he didn't start the Conference League final - while Reece James' minutes have to be managed to an extent that the club captain didn't start a European final.
My point is, they probably need to strengthen everywhere other than central midfield if they can afford it. But where is the most vital?
For me, they have to address the goalkeeper position after Delap arrives. Robert Sanchez started and finished the season as first choice, but he didn't convince at all and lost his spot as No.1 to Filip Jorgensen at one stage. Are any of their current loan army capable of displacing him? Probably, but if they were that good they'd already have been challenging for a place.
They should be going all out for someone like Caoimhin Kelleher or Jan Oblak to make an immediate improvement to the starting XI; it will cost them, but earn them points in the process.
You may also like
Mass shooting at house party in Hickory, North Carolina: 1 dead, 11 injured
Lee Anderson warns of stark wake-up call over small boats crisis
Senior citizen defrauding people by impersonating Colonel arrested from Punjab
Sam Gardiner dead: BBC Race Across the World star, 24, dies after tragic car crash
Bihar: Motihari beneficiaries count benefits of Ayushman Bharat scheme, thank govt