Gittens completing an international transfer means five per cent of the fee paid by Chelsea, or £2.4m, is distributed as a solidarity payment to those clubs with a hand in his development up to the age of 23. The catch here is Gittens is still only 20, so Dortmund also retain a majority of that sum.

A deal to sign Gittens was struck late last month and Dortmund revealed on Thursday that the young winger was on the cusp of signing for Chelsea, who are reported to have paid an initial £48.5 million ($66.2 million) with a further £3.5 million ($4.8 million) in add-ons.

Chelsea are ready to continue their summer spending with the signing of Jamie Gittens, having agreed a £55million deal with Borussia Dortmund, who've released a statement