Liverpool have been the biggest spenders, Arsenal did their business early, Chelsea came up on the rails late while Manchester United and Tottenham Hotspur have endured frustrating summers.
The Blues have now announced on Chelseafc.com that Kovacic will join the club on a season-long loan deal with Courtois heading to Spain in the opposite direction, subject to agreeing personal terms and completing a medical.
With so many incomings, Chelsea will need to trim the squad and the prominent candidate for a move away seems to be French midfielder Tiemoue Bakayoko.
New Chelsea boss Maurizio Sarri appears to have decided he can make do without Bakayoko for the forthcoming season.
It remains to be seen how quickly AC Milan will seal the deal.
"A few other clubs in the Premier League also interested in him".
Courtois has been trying to force his way out of Stamford Bridge this summer after refusing to sign a new contract and Chelsea have made a decision to cash-in rather than risk losing him for nothing next summer.
It's now believed that Everton want Bakayoko, but AC Milan are currently in the driving seat according to the report, with Borussia Dortmund also interested, leaving the Toffees with work to do if they want Bakayoko before Thursday's 5pm deadline.