But no sooner was the ink on his contract dry, the Blues were being linked with yet another attacking midfielder, this time Porto's Ghanaian winger Christian Atsu.
Given the attacking talent they have at their disposal, it's somewhat of a surprising development that the Blues are looking to add more firepower to their ranks.
So where will Atsu fit in?
What's his playing style? Who will he replace in the Blues' lineup? Bleacher Report digs a little deeper to find out.
Who is He?
Aged just 21 years old, Christian Atsu remains a raw talent with less than 20 league appearances to his name for current club Porto.
In fact, with 16 caps for his country—one game less than he has played at Porto—Atsu's experience on the international stage rivals that of his club.
He was scouted as a teenager in his homeland, being signed by Porto as a 17-year-old and was soon under the guise of another former Porto manager connected to Chelsea—Andre Villas-Boas, who included him among his substitutes at various stages of the 2010-11 season.
Atsu spent the following year on loan at Rio Ave, making enough of an impression to convince Porto he was ready for a regular spot in their first team last term.
With Chelsea now among his admirers, it's the Ghana international wasting no time in making his mark on the European game.
With his electric pace and quick feet, Atsu does much of his scheming out on the flanks, primarily playing as a left winger.
As you would expect, he enjoys exposing his opposite number and using his skill to good effect, creating space and opportunities for his teammates.
Atsu has also played behind the striker at times, although his scoring record suggest he needs to improve his strike rate to be taken seriously in a more central position.
Where Would He Fit In?
Although Chelsea have their documented array of attacking talent, they lack out-and-out wingers, with Hazard, Mata, Oscar and Willian more comfortable through the middle. Schurrle can play wide right, leaving the possibility for Jose Mourinho to utilize Atsu's abilities on the left, adding more width to Chelsea's game.
The Blues can congest the midfield area at times, so Atsu's potential arrival could bring them an alternative to their more familiar lineup behind the main striker.
Who Would Atsu Replace?
It's going to take some effort to dislodge players of the ilk of Hazard and Oscar at Chelsea. Atsu may be a similar age to those currently at Stamford Bridge, but he lacks experience and Chelsea needs to add a little more into their starting lineup, rather than reducing it.
Should Atsu arrive, the likely casualty would be Victor Moses. The former Crystal Palace and Wigan Athletic man enjoyed a solid debut campaign with the Blues last year, but as ever, there are always casualties when a new manager arrives and it seems Moses is that man at Chelsea right now.
He hasn't appeared in any of Chelsea's three games this season and with more talent flooding into West London, it's unlikely he will.
Should Chelsea Buy Him?
If Jose Mourinho is playing a numbers game with his Chelsea squad. Mourinho is already close to overcrowding the Stamford Bridge dressing room. Adding Atsu will make this Chelsea squad even more imbalanced than we have initially thought.
Alongside their big names in attacking positions, Chelsea also have the likes of Lucas Piazon on loan beyond 2013-14, things are looking even more crowded than they appear.
With Chelsea's move for the Porto star coming somewhat as a bolt from the blue, it's difficult to see the logic behind this move, especially as Willian has not long arrived from Anzhi Makhachkala.
Watch highlights of Christian Atsu in action for Ghana against Niger in May 2013.
Garry Hayes is Bleacher Report's lead Chelsea correspondent and will be following the club from a London base throughout the 2013-14 season. Follow him on Twitter here @garryhayes