Chelsea reportedly made a last-gasp bid to sign World Cup star Sofyan Amrabat, leading to a row with Fiorentina, while completing the British record £107million signing of Enzo Fernandez.
Co-owner Behdad Eghbali also turned up in Turkey unannounced to steal £88m signing Mykhailo Mudryk from under the noses of rivals Arsenal.
But the club's transfer strategy - which led to a record outlay of £323m in the January window - has apparently left executives at rival clubs perplexed.
The New York Times has revealed how Chelsea's busy window took a further twist on deadline day when Todd Boehly tried to sign Moroccan midfielder Amrabat while other executives were working on the Fernandez deal with Benfica.