The Blues have seemingly focused on the acquisition of youth, having signed teenage quartet Lucas Piazon, Thibaut Courtois, Oriol Romeu and Romelu Lukaku, as well as 20-year-old Mexican Ulises Davilla.
Chelsea have, however, also added Juan Mata - a relative senior pro at 23 - to their ranks for upwards of £20 million, although the spending still remains less than that of the winter transfer window.
But, if reports are to be believed, another marquee signing could be completed before the tonight's transfer deadline, with Chelsea allegedly in advanced talks with a number of targets.
One of those is said to be Porto full-back Alvaro Pereira, with Andre Villas-Boas keen to link up with his former charge.
Chelsea have already had one offer for the Uruguay international rejected, with Pereira's release clause standing at £26 million.
But, says his agent, the two clubs are in discussions over a proposed deal.
"I know that the clubs are talking. This is a positive sign. What I know from Chelsea is that they are trying. One can only hope," Alejandro Savich told Maisfutebol.
"Right now, Alvaro Pereira is waiting while the clubs talk. We have not spoken with Chelsea because I'm not allowed to do so. It is essential Porto and Chelsea reach an agreement first.
Meanwhile, reports in Wednesday's press claimed Chelsea were considering a last-ditch bid for Bayern Munich winger Franck Ribery.
According to The Sun, the German giants want £36 million for the France international, but Chelsea will only offer £30 million for his services.